distribution/registry/storage/signedmanifesthandler.go

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package storage
import (
"encoding/json"
"fmt"
"github.com/docker/distribution"
"github.com/docker/distribution/context"
"github.com/docker/distribution/digest"
"github.com/docker/distribution/manifest/schema1"
"github.com/docker/distribution/reference"
"github.com/docker/libtrust"
)
// signedManifestHandler is a ManifestHandler that covers schema1 manifests. It
// can unmarshal and put schema1 manifests that have been signed by libtrust.
type signedManifestHandler struct {
repository *repository
blobStore *linkedBlobStore
ctx context.Context
signatures *signatureStore
}
var _ ManifestHandler = &signedManifestHandler{}
func (ms *signedManifestHandler) Unmarshal(ctx context.Context, dgst digest.Digest, content []byte) (distribution.Manifest, error) {
context.GetLogger(ms.ctx).Debug("(*signedManifestHandler).Unmarshal")
var (
signatures [][]byte
err error
)
if ms.repository.schema1SignaturesEnabled {
// Fetch the signatures for the manifest
signatures, err = ms.signatures.Get(dgst)
if err != nil {
return nil, err
}
}
jsig, err := libtrust.NewJSONSignature(content, signatures...)
if err != nil {
return nil, err
}
if ms.repository.schema1SigningKey != nil {
if err := jsig.Sign(ms.repository.schema1SigningKey); err != nil {
return nil, err
}
} else if !ms.repository.schema1SignaturesEnabled {
return nil, fmt.Errorf("missing signing key with signature store disabled")
}
// Extract the pretty JWS
raw, err := jsig.PrettySignature("signatures")
if err != nil {
return nil, err
}
var sm schema1.SignedManifest
if err := json.Unmarshal(raw, &sm); err != nil {
return nil, err
}
return &sm, nil
}
func (ms *signedManifestHandler) Put(ctx context.Context, manifest distribution.Manifest, skipDependencyVerification bool) (digest.Digest, error) {
context.GetLogger(ms.ctx).Debug("(*signedManifestHandler).Put")
sm, ok := manifest.(*schema1.SignedManifest)
if !ok {
return "", fmt.Errorf("non-schema1 manifest put to signedManifestHandler: %T", manifest)
}
if err := ms.verifyManifest(ms.ctx, *sm, skipDependencyVerification); err != nil {
return "", err
}
mt := schema1.MediaTypeManifest
payload := sm.Canonical
revision, err := ms.blobStore.Put(ctx, mt, payload)
if err != nil {
context.GetLogger(ctx).Errorf("error putting payload into blobstore: %v", err)
return "", err
}
// Link the revision into the repository.
if err := ms.blobStore.linkBlob(ctx, revision); err != nil {
return "", err
}
if ms.repository.schema1SignaturesEnabled {
// Grab each json signature and store them.
signatures, err := sm.Signatures()
if err != nil {
return "", err
}
if err := ms.signatures.Put(revision.Digest, signatures...); err != nil {
return "", err
}
}
return revision.Digest, nil
}
// verifyManifest ensures that the manifest content is valid from the
// perspective of the registry. It ensures that the signature is valid for the
// enclosed payload. As a policy, the registry only tries to store valid
// content, leaving trust policies of that content up to consumers.
func (ms *signedManifestHandler) verifyManifest(ctx context.Context, mnfst schema1.SignedManifest, skipDependencyVerification bool) error {
var errs distribution.ErrManifestVerification
if len(mnfst.Name) > reference.NameTotalLengthMax {
errs = append(errs,
distribution.ErrManifestNameInvalid{
Name: mnfst.Name,
Reason: fmt.Errorf("manifest name must not be more than %v characters", reference.NameTotalLengthMax),
})
}
if !reference.NameRegexp.MatchString(mnfst.Name) {
errs = append(errs,
distribution.ErrManifestNameInvalid{
Name: mnfst.Name,
Reason: fmt.Errorf("invalid manifest name format"),
})
}
if len(mnfst.History) != len(mnfst.FSLayers) {
errs = append(errs, fmt.Errorf("mismatched history and fslayer cardinality %d != %d",
len(mnfst.History), len(mnfst.FSLayers)))
}
if _, err := schema1.Verify(&mnfst); err != nil {
switch err {
case libtrust.ErrMissingSignatureKey, libtrust.ErrInvalidJSONContent, libtrust.ErrMissingSignatureKey:
errs = append(errs, distribution.ErrManifestUnverified{})
default:
if err.Error() == "invalid signature" { // TODO(stevvooe): This should be exported by libtrust
errs = append(errs, distribution.ErrManifestUnverified{})
} else {
errs = append(errs, err)
}
}
}
if !skipDependencyVerification {
for _, fsLayer := range mnfst.References() {
_, err := ms.repository.Blobs(ctx).Stat(ctx, fsLayer.Digest)
if err != nil {
if err != distribution.ErrBlobUnknown {
errs = append(errs, err)
}
// On error here, we always append unknown blob errors.
errs = append(errs, distribution.ErrManifestBlobUnknown{Digest: fsLayer.Digest})
}
}
}
if len(errs) != 0 {
return errs
}
return nil
}