func (p *v2Puller) download(di *downloadInfo) {
logrus.Debugf("pulling blob %q to %s", di.digest, di.img.id)
blobs := p.repo.Blobs(context.Background())
desc, err := blobs.Stat(context.Background(), di.digest)
if err != nil {
logrus.Debugf("Error statting layer: %v", err)
di.err <- err
return
}
di.size = desc.Size
layerDownload, err := blobs.Open(context.Background(), di.digest)
if err != nil {
logrus.Debugf("Error fetching layer: %v", err)
di.err <- err
return
}
defer layerDownload.Close()
verifier, err := digest.NewDigestVerifier(di.digest)
if err != nil {
di.err <- err
return
}
reader := progressreader.New(progressreader.Config{
In: ioutil.NopCloser(io.TeeReader(layerDownload, verifier)),
Out: di.broadcaster,
Formatter: p.sf,
Size: di.size,
NewLines: false,
ID: stringid.TruncateID(di.img.id),
Action: "Downloading",
})
io.Copy(di.tmpFile, reader)
di.broadcaster.Write(p.sf.FormatProgress(stringid.TruncateID(di.img.id), "Verifying Checksum", nil))
if !verifier.Verified() {
err = fmt.Errorf("filesystem layer verification failed for digest %s", di.digest)
logrus.Error(err)
di.err <- err
return
}
di.broadcaster.Write(p.sf.FormatProgress(stringid.TruncateID(di.img.id), "Download complete", nil))
logrus.Debugf("Downloaded %s to tempfile %s", di.img.id, di.tmpFile.Name())
di.layer = layerDownload
di.err <- nil
}
// Finally Push the (signed) manifest of the blobs we've just pushed
func (r *Session) PutV2ImageManifest(ep *Endpoint, imageName, tagName string, signedManifest, rawManifest []byte, auth *RequestAuthorization) (digest.Digest, error) {
routeURL, err := getV2Builder(ep).BuildManifestURL(imageName, tagName)
if err != nil {
return "", err
}
method := "PUT"
log.Debugf("[registry] Calling %q %s", method, routeURL)
req, err := r.reqFactory.NewRequest(method, routeURL, bytes.NewReader(signedManifest))
if err != nil {
return "", err
}
if err := auth.Authorize(req); err != nil {
return "", err
}
res, _, err := r.doRequest(req)
if err != nil {
return "", err
}
defer res.Body.Close()
// All 2xx and 3xx responses can be accepted for a put.
if res.StatusCode >= 400 {
if res.StatusCode == 401 {
return "", errLoginRequired
}
errBody, err := ioutil.ReadAll(res.Body)
if err != nil {
return "", err
}
log.Debugf("Unexpected response from server: %q %#v", errBody, res.Header)
return "", utils.NewHTTPRequestError(fmt.Sprintf("Server error: %d trying to push %s:%s manifest", res.StatusCode, imageName, tagName), res)
}
hdrDigest, err := digest.ParseDigest(res.Header.Get(DockerDigestHeader))
if err != nil {
return "", fmt.Errorf("invalid manifest digest from registry: %s", err)
}
dgstVerifier, err := digest.NewDigestVerifier(hdrDigest)
if err != nil {
return "", fmt.Errorf("invalid manifest digest from registry: %s", err)
}
dgstVerifier.Write(rawManifest)
if !dgstVerifier.Verified() {
computedDigest, _ := digest.FromBytes(rawManifest)
return "", fmt.Errorf("unable to verify manifest digest: registry has %q, computed %q", hdrDigest, computedDigest)
}
return hdrDigest, nil
}
func verifyManifest(signedManifest *manifest.SignedManifest, tag string) (m *manifest.Manifest, err error) {
// If pull by digest, then verify the manifest digest. NOTE: It is
// important to do this first, before any other content validation. If the
// digest cannot be verified, don't even bother with those other things.
if manifestDigest, err := digest.ParseDigest(tag); err == nil {
verifier, err := digest.NewDigestVerifier(manifestDigest)
if err != nil {
return nil, err
}
payload, err := signedManifest.Payload()
if err != nil {
// If this failed, the signatures section was corrupted
// or missing. Treat the entire manifest as the payload.
payload = signedManifest.Raw
}
if _, err := verifier.Write(payload); err != nil {
return nil, err
}
if !verifier.Verified() {
err := fmt.Errorf("image verification failed for digest %s", manifestDigest)
logrus.Error(err)
return nil, err
}
var verifiedManifest manifest.Manifest
if err = json.Unmarshal(payload, &verifiedManifest); err != nil {
return nil, err
}
m = &verifiedManifest
} else {
m = &signedManifest.Manifest
}
if m.SchemaVersion != 1 {
return nil, fmt.Errorf("unsupported schema version %d for tag %q", m.SchemaVersion, tag)
}
if len(m.FSLayers) != len(m.History) {
return nil, fmt.Errorf("length of history not equal to number of layers for tag %q", tag)
}
if len(m.FSLayers) == 0 {
return nil, fmt.Errorf("no FSLayers in manifest for tag %q", tag)
}
return m, nil
}
// loadManifest loads a manifest from a byte array and verifies its content.
// The signature must be verified or an error is returned. If the manifest
// contains no signatures by a trusted key for the name in the manifest, the
// image is not considered verified. The parsed manifest object and a boolean
// for whether the manifest is verified is returned.
func (s *TagStore) loadManifest(eng *engine.Engine, manifestBytes []byte, dgst, ref string) (*registry.ManifestData, bool, error) {
sig, err := libtrust.ParsePrettySignature(manifestBytes, "signatures")
if err != nil {
return nil, false, fmt.Errorf("error parsing payload: %s", err)
}
keys, err := sig.Verify()
if err != nil {
return nil, false, fmt.Errorf("error verifying payload: %s", err)
}
payload, err := sig.Payload()
if err != nil {
return nil, false, fmt.Errorf("error retrieving payload: %s", err)
}
var manifestDigest digest.Digest
if dgst != "" {
manifestDigest, err = digest.ParseDigest(dgst)
if err != nil {
return nil, false, fmt.Errorf("invalid manifest digest from registry: %s", err)
}
dgstVerifier, err := digest.NewDigestVerifier(manifestDigest)
if err != nil {
return nil, false, fmt.Errorf("unable to verify manifest digest from registry: %s", err)
}
dgstVerifier.Write(payload)
if !dgstVerifier.Verified() {
computedDigest, _ := digest.FromBytes(payload)
return nil, false, fmt.Errorf("unable to verify manifest digest: registry has %q, computed %q", manifestDigest, computedDigest)
}
}
if utils.DigestReference(ref) && ref != manifestDigest.String() {
return nil, false, fmt.Errorf("mismatching image manifest digest: got %q, expected %q", manifestDigest, ref)
}
var manifest registry.ManifestData
if err := json.Unmarshal(payload, &manifest); err != nil {
return nil, false, fmt.Errorf("error unmarshalling manifest: %s", err)
}
if manifest.SchemaVersion != 1 {
return nil, false, fmt.Errorf("unsupported schema version: %d", manifest.SchemaVersion)
}
var verified bool
for _, key := range keys {
job := eng.Job("trust_key_check")
b, err := key.MarshalJSON()
if err != nil {
return nil, false, fmt.Errorf("error marshalling public key: %s", err)
}
namespace := manifest.Name
if namespace[0] != '/' {
namespace = "/" + namespace
}
stdoutBuffer := bytes.NewBuffer(nil)
job.Args = append(job.Args, namespace)
job.Setenv("PublicKey", string(b))
// Check key has read/write permission (0x03)
job.SetenvInt("Permission", 0x03)
job.Stdout.Add(stdoutBuffer)
if err = job.Run(); err != nil {
return nil, false, fmt.Errorf("error running key check: %s", err)
}
result := engine.Tail(stdoutBuffer, 1)
log.Debugf("Key check result: %q", result)
if result == "verified" {
verified = true
}
}
return &manifest, verified, nil
}
// validateBlob checks the data against the digest, returning an error if it
// does not match. The canonical descriptor is returned.
func (bw *blobWriter) validateBlob(ctx context.Context, desc distribution.Descriptor) (distribution.Descriptor, error) {
var (
verified, fullHash bool
canonical digest.Digest
)
if desc.Digest == "" {
// if no descriptors are provided, we have nothing to validate
// against. We don't really want to support this for the registry.
return distribution.Descriptor{}, distribution.ErrBlobInvalidDigest{
Reason: fmt.Errorf("cannot validate against empty digest"),
}
}
// Stat the on disk file
if fi, err := bw.bufferedFileWriter.driver.Stat(ctx, bw.path); err != nil {
switch err := err.(type) {
case storagedriver.PathNotFoundError:
// NOTE(stevvooe): We really don't care if the file is
// not actually present for the reader. We now assume
// that the desc length is zero.
desc.Size = 0
default:
// Any other error we want propagated up the stack.
return distribution.Descriptor{}, err
}
} else {
if fi.IsDir() {
return distribution.Descriptor{}, fmt.Errorf("unexpected directory at upload location %q", bw.path)
}
bw.size = fi.Size()
}
if desc.Size > 0 {
if desc.Size != bw.size {
return distribution.Descriptor{}, distribution.ErrBlobInvalidLength
}
} else {
// if provided 0 or negative length, we can assume caller doesn't know or
// care about length.
desc.Size = bw.size
}
// TODO(stevvooe): This section is very meandering. Need to be broken down
// to be a lot more clear.
if err := bw.resumeDigestAt(ctx, bw.size); err == nil {
canonical = bw.digester.Digest()
if canonical.Algorithm() == desc.Digest.Algorithm() {
// Common case: client and server prefer the same canonical digest
// algorithm - currently SHA256.
verified = desc.Digest == canonical
} else {
// The client wants to use a different digest algorithm. They'll just
// have to be patient and wait for us to download and re-hash the
// uploaded content using that digest algorithm.
fullHash = true
}
} else if err == errResumableDigestNotAvailable {
// Not using resumable digests, so we need to hash the entire layer.
fullHash = true
} else {
return distribution.Descriptor{}, err
}
if fullHash {
// a fantastic optimization: if the the written data and the size are
// the same, we don't need to read the data from the backend. This is
// because we've written the entire file in the lifecycle of the
// current instance.
if bw.written == bw.size && digest.Canonical == desc.Digest.Algorithm() {
canonical = bw.digester.Digest()
verified = desc.Digest == canonical
}
// If the check based on size fails, we fall back to the slowest of
// paths. We may be able to make the size-based check a stronger
// guarantee, so this may be defensive.
if !verified {
digester := digest.Canonical.New()
digestVerifier, err := digest.NewDigestVerifier(desc.Digest)
if err != nil {
return distribution.Descriptor{}, err
}
// Read the file from the backend driver and validate it.
fr, err := newFileReader(ctx, bw.bufferedFileWriter.driver, bw.path, desc.Size)
if err != nil {
return distribution.Descriptor{}, err
}
tr := io.TeeReader(fr, digester.Hash())
if _, err := io.Copy(digestVerifier, tr); err != nil {
return distribution.Descriptor{}, err
}
canonical = digester.Digest()
verified = digestVerifier.Verified()
}
}
if !verified {
context.GetLoggerWithFields(ctx,
map[string]interface{}{
"canonical": canonical,
"provided": desc.Digest,
}, "canonical", "provided").
Errorf("canonical digest does match provided digest")
return distribution.Descriptor{}, distribution.ErrBlobInvalidDigest{
Digest: desc.Digest,
Reason: fmt.Errorf("content does not match digest"),
}
}
// update desc with canonical hash
desc.Digest = canonical
if desc.MediaType == "" {
desc.MediaType = "application/octet-stream"
}
return desc, nil
}
func (s *TagStore) pullV2Tag(eng *engine.Engine, r *registry.Session, out io.Writer, endpoint *registry.Endpoint, repoInfo *registry.RepositoryInfo, tag string, sf *utils.StreamFormatter, parallel bool, auth *registry.RequestAuthorization) (bool, error) {
log.Debugf("Pulling tag from V2 registry: %q", tag)
manifestBytes, manifestDigest, err := r.GetV2ImageManifest(endpoint, repoInfo.RemoteName, tag, auth)
if err != nil {
return false, err
}
// loadManifest ensures that the manifest payload has the expected digest
// if the tag is a digest reference.
manifest, verified, err := s.loadManifest(eng, manifestBytes, manifestDigest, tag)
if err != nil {
return false, fmt.Errorf("error verifying manifest: %s", err)
}
if err := checkValidManifest(manifest); err != nil {
return false, err
}
if verified {
log.Printf("Image manifest for %s has been verified", utils.ImageReference(repoInfo.CanonicalName, tag))
}
out.Write(sf.FormatStatus(tag, "Pulling from %s", repoInfo.CanonicalName))
downloads := make([]downloadInfo, len(manifest.FSLayers))
for i := len(manifest.FSLayers) - 1; i >= 0; i-- {
var (
sumStr = manifest.FSLayers[i].BlobSum
imgJSON = []byte(manifest.History[i].V1Compatibility)
)
img, err := image.NewImgJSON(imgJSON)
if err != nil {
return false, fmt.Errorf("failed to parse json: %s", err)
}
downloads[i].img = img
// Check if exists
if s.graph.Exists(img.ID) {
log.Debugf("Image already exists: %s", img.ID)
continue
}
dgst, err := digest.ParseDigest(sumStr)
if err != nil {
return false, err
}
downloads[i].digest = dgst
out.Write(sf.FormatProgress(stringid.TruncateID(img.ID), "Pulling fs layer", nil))
downloadFunc := func(di *downloadInfo) error {
log.Debugf("pulling blob %q to V1 img %s", sumStr, img.ID)
if c, err := s.poolAdd("pull", "img:"+img.ID); err != nil {
if c != nil {
out.Write(sf.FormatProgress(stringid.TruncateID(img.ID), "Layer already being pulled by another client. Waiting.", nil))
<-c
out.Write(sf.FormatProgress(stringid.TruncateID(img.ID), "Download complete", nil))
} else {
log.Debugf("Image (id: %s) pull is already running, skipping: %v", img.ID, err)
}
} else {
defer s.poolRemove("pull", "img:"+img.ID)
tmpFile, err := ioutil.TempFile("", "GetV2ImageBlob")
if err != nil {
return err
}
r, l, err := r.GetV2ImageBlobReader(endpoint, repoInfo.RemoteName, di.digest.Algorithm(), di.digest.Hex(), auth)
if err != nil {
return err
}
defer r.Close()
verifier, err := digest.NewDigestVerifier(di.digest)
if err != nil {
return err
}
if _, err := io.Copy(tmpFile, progressreader.New(progressreader.Config{
In: ioutil.NopCloser(io.TeeReader(r, verifier)),
Out: out,
Formatter: sf,
Size: int(l),
NewLines: false,
ID: stringid.TruncateID(img.ID),
Action: "Downloading",
})); err != nil {
return fmt.Errorf("unable to copy v2 image blob data: %s", err)
}
out.Write(sf.FormatProgress(stringid.TruncateID(img.ID), "Verifying Checksum", nil))
if !verifier.Verified() {
log.Infof("Image verification failed: checksum mismatch for %q", di.digest.String())
verified = false
}
out.Write(sf.FormatProgress(stringid.TruncateID(img.ID), "Download complete", nil))
log.Debugf("Downloaded %s to tempfile %s", img.ID, tmpFile.Name())
di.tmpFile = tmpFile
di.length = l
di.downloaded = true
}
di.imgJSON = imgJSON
return nil
}
if parallel {
downloads[i].err = make(chan error)
go func(di *downloadInfo) {
di.err <- downloadFunc(di)
}(&downloads[i])
} else {
err := downloadFunc(&downloads[i])
if err != nil {
return false, err
}
}
}
var tagUpdated bool
for i := len(downloads) - 1; i >= 0; i-- {
d := &downloads[i]
if d.err != nil {
err := <-d.err
if err != nil {
return false, err
}
}
if d.downloaded {
// if tmpFile is empty assume download and extracted elsewhere
defer os.Remove(d.tmpFile.Name())
defer d.tmpFile.Close()
d.tmpFile.Seek(0, 0)
if d.tmpFile != nil {
err = s.graph.Register(d.img,
progressreader.New(progressreader.Config{
In: d.tmpFile,
Out: out,
Formatter: sf,
Size: int(d.length),
ID: stringid.TruncateID(d.img.ID),
Action: "Extracting",
}))
if err != nil {
return false, err
}
// FIXME: Pool release here for parallel tag pull (ensures any downloads block until fully extracted)
}
out.Write(sf.FormatProgress(stringid.TruncateID(d.img.ID), "Pull complete", nil))
tagUpdated = true
} else {
out.Write(sf.FormatProgress(stringid.TruncateID(d.img.ID), "Already exists", nil))
}
}
// Check for new tag if no layers downloaded
if !tagUpdated {
repo, err := s.Get(repoInfo.LocalName)
if err != nil {
return false, err
}
if repo != nil {
if _, exists := repo[tag]; !exists {
tagUpdated = true
}
}
}
if verified && tagUpdated {
out.Write(sf.FormatStatus(utils.ImageReference(repoInfo.CanonicalName, tag), "The image you are pulling has been verified. Important: image verification is a tech preview feature and should not be relied on to provide security."))
}
if manifestDigest != "" {
out.Write(sf.FormatStatus("", "Digest: %s", manifestDigest))
}
if utils.DigestReference(tag) {
if err = s.SetDigest(repoInfo.LocalName, tag, downloads[0].img.ID); err != nil {
return false, err
}
} else {
// only set the repository/tag -> image ID mapping when pulling by tag (i.e. not by digest)
if err = s.Set(repoInfo.LocalName, tag, downloads[0].img.ID, true); err != nil {
return false, err
}
}
return tagUpdated, nil
}
