Crypto library movement and changes to content helper interfaces

Signed-off-by: Derek McGowan <derek@mcgstyle.net>

cmd/ctr/commands/images/crypt_utils.go

@@ -28,10 +28,11 @@ import (
 
 	"github.com/containerd/containerd"
 	"github.com/containerd/containerd/images"
-	"github.com/containerd/containerd/images/encryption"
-	encconfig "github.com/containerd/containerd/images/encryption/config"
-	encutils "github.com/containerd/containerd/images/encryption/utils"
+	imgenc "github.com/containerd/containerd/images/encryption"
 	"github.com/containerd/containerd/leases"
+	"github.com/containerd/containerd/pkg/encryption"
+	encconfig "github.com/containerd/containerd/pkg/encryption/config"
+	encutils "github.com/containerd/containerd/pkg/encryption/utils"
 	"github.com/containerd/containerd/platforms"
 
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
@@ -209,7 +210,7 @@ func getGPGPrivateKeys(context *cli.Context, gpgSecretKeyRingFiles [][]byte, des
 	return encryption.GPGGetPrivateKey(descs, gpgClient, gpgVault, mustFindKey, dcparameters)
 }
 
-func createLayerFilter(client *containerd.Client, ctx gocontext.Context, desc ocispec.Descriptor, layers []int32, platformList []ocispec.Platform) (images.LayerFilter, error) {
+func createLayerFilter(client *containerd.Client, ctx gocontext.Context, desc ocispec.Descriptor, layers []int32, platformList []ocispec.Platform) (imgenc.LayerFilter, error) {
 	alldescs, err := images.GetImageLayerDescriptors(ctx, client.ContentStore(), desc)
 	if err != nil {
 		return nil, err
@@ -261,9 +262,9 @@ func cryptImage(client *containerd.Client, ctx gocontext.Context, name, newName
 	defer ls.Delete(ctx, l, leases.SynchronousDelete)
 
 	if encrypt {
-		newSpec, modified, err = images.EncryptImage(ctx, client.ContentStore(), ls, l, image.Target, cc, lf)
+		newSpec, modified, err = imgenc.EncryptImage(ctx, client.ContentStore(), ls, l, image.Target, cc, lf)
 	} else {
-		newSpec, modified, err = images.DecryptImage(ctx, client.ContentStore(), ls, l, image.Target, cc, lf)
+		newSpec, modified, err = imgenc.DecryptImage(ctx, client.ContentStore(), ls, l, image.Target, cc, lf)
 	}
 	if err != nil {
 		return image, err

cmd/ctr/commands/images/decrypt.go

@@ -20,8 +20,8 @@ import (
 	"fmt"
 
 	"github.com/containerd/containerd/cmd/ctr/commands"
-	"github.com/containerd/containerd/images"
-	encconfig "github.com/containerd/containerd/images/encryption/config"
+	imgenc "github.com/containerd/containerd/images/encryption"
+	encconfig "github.com/containerd/containerd/pkg/encryption/config"
 	"github.com/pkg/errors"
 	"github.com/urfave/cli"
 )
@@ -77,7 +77,7 @@ var decryptCommand = cli.Command{
 			return err
 		}
 
-		isEncrypted := images.HasEncryptedLayer(ctx, descs)
+		isEncrypted := imgenc.HasEncryptedLayer(ctx, descs)
 		if !isEncrypted {
 			fmt.Printf("Nothing to decrypted.\n")
 			return nil

cmd/ctr/commands/images/encrypt.go

@@ -20,7 +20,7 @@ import (
 	"fmt"
 
 	"github.com/containerd/containerd/cmd/ctr/commands"
-	encconfig "github.com/containerd/containerd/images/encryption/config"
+	encconfig "github.com/containerd/containerd/pkg/encryption/config"
 	"github.com/pkg/errors"
 	"github.com/urfave/cli"
 )

cmd/ctr/commands/images/layerinfo.go

@@ -24,7 +24,7 @@ import (
 	"text/tabwriter"
 
 	"github.com/containerd/containerd/cmd/ctr/commands"
-	"github.com/containerd/containerd/images/encryption"
+	"github.com/containerd/containerd/pkg/encryption"
 	"github.com/containerd/containerd/platforms"
 
 	"github.com/pkg/errors"

content/helpers.go

@@ -87,46 +87,6 @@ func WriteBlob(ctx context.Context, cs Ingester, ref string, r io.Reader, desc o
 	return Copy(ctx, cw, r, desc.Size, desc.Digest, opts...)
 }
 
-// WriteBlobBlind writes data without expected digest into the content store. If
-// expected already exists, the method returns immediately and the reader will
-// not be consumed.
-//
-// This is useful when the digest and size are NOT known beforehand.
-//
-// Copy is buffered, so no need to wrap reader in buffered io.
-func WriteBlobBlind(ctx context.Context, cs Ingester, ref string, r io.Reader, opts ...Opt) (digest.Digest, int64, error) {
-	cw, err := OpenWriter(ctx, cs, WithRef(ref))
-	if err != nil {
-		return "", 0, errors.Wrap(err, "failed to open writer")
-	}
-	defer cw.Close()
-
-	ws, err := cw.Status()
-	if err != nil {
-		return "", 0, errors.Wrap(err, "failed to get status")
-	}
-
-	if ws.Offset > 0 {
-		// not needed
-		return "", 0, errors.New("ws.Offset > 0 is not supported")
-	}
-
-	size, err := copyWithBuffer(cw, r)
-	if err != nil {
-		return "", 0, errors.Wrap(err, "failed to copy")
-	}
-
-	digest := cw.Digest()
-
-	if err := cw.Commit(ctx, size, digest); err != nil {
-		if !errdefs.IsAlreadyExists(err) {
-			return "", 0, errors.Wrapf(err, "failed commit block")
-		}
-	}
-
-	return digest, size, err
-}
-
 // OpenWriter opens a new writer for the given reference, retrying if the writer
 // is locked until the reference is available or returns an error.
 func OpenWriter(ctx context.Context, cs Ingester, opts ...WriterOpt) (Writer, error) {
@@ -209,6 +169,28 @@ func CopyReaderAt(cw Writer, ra ReaderAt, n int64) error {
 	return err
 }
 
+// CopyReader copies to a writer from a given reader, returning
+// the number of bytes copied.
+// Note: if the writer has a non-zero offset, the total number
+// of bytes read may be greater than those copied if the reader
+// is not an io.Seeker.
+// This copy does not commit the writer.
+func CopyReader(cw Writer, r io.Reader) (int64, error) {
+	ws, err := cw.Status()
+	if err != nil {
+		return 0, errors.Wrap(err, "failed to get status")
+	}
+
+	if ws.Offset > 0 {
+		r, err = seekReader(r, ws.Offset, 0)
+		if err != nil {
+			return 0, errors.Wrapf(err, "unable to resume write to %v", ws.Ref)
+		}
+	}
+
+	return copyWithBuffer(cw, r)
+}
+
 // seekReader attempts to seek the reader to the given offset, either by
 // resolving `io.Seeker`, by detecting `io.ReaderAt`, or discarding
 // up to the given offset.

image_enc_test.go

@@ -25,9 +25,10 @@ import (
 	"github.com/containerd/containerd/content"
 	"github.com/containerd/containerd/errdefs"
 	"github.com/containerd/containerd/images"
-	encconfig "github.com/containerd/containerd/images/encryption/config"
-	"github.com/containerd/containerd/images/encryption/utils"
+	imgenc "github.com/containerd/containerd/images/encryption"
 	"github.com/containerd/containerd/leases"
+	encconfig "github.com/containerd/containerd/pkg/encryption/config"
+	"github.com/containerd/containerd/pkg/encryption/utils"
 	"github.com/containerd/containerd/platforms"
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 )
@@ -142,7 +143,7 @@ func TestImageEncryption(t *testing.T) {
 	defer ls.Delete(ctx, l, leases.SynchronousDelete)
 
 	// Perform encryption of image
-	encSpec, modified, err := images.EncryptImage(ctx, client.ContentStore(), ls, l, image.Target, cc, lf)
+	encSpec, modified, err := imgenc.EncryptImage(ctx, client.ContentStore(), ls, l, image.Target, cc, lf)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -180,7 +181,7 @@ func TestImageEncryption(t *testing.T) {
 	}
 	defer ls.Delete(ctx, l, leases.SynchronousDelete)
 
-	decSpec, modified, err := images.DecryptImage(ctx, client.ContentStore(), ls, l, encSpec, cc, lf)
+	decSpec, modified, err := imgenc.DecryptImage(ctx, client.ContentStore(), ls, l, encSpec, cc, lf)
 	if err != nil {
 		t.Fatal(err)
 	}

images/enc_utils.go

@@ -1,451 +0,0 @@
-/*
-   Copyright The containerd Authors.
-
-   Licensed under the Apache License, Version 2.0 (the "License");
-   you may not use this file except in compliance with the License.
-   You may obtain a copy of the License at
-
-       http://www.apache.org/licenses/LICENSE-2.0
-
-   Unless required by applicable law or agreed to in writing, software
-   distributed under the License is distributed on an "AS IS" BASIS,
-   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-   See the License for the specific language governing permissions and
-   limitations under the License.
-*/
-
-package images
-
-import (
-	"bytes"
-	"context"
-	"encoding/json"
-	"fmt"
-	"io"
-	"math/rand"
-
-	"github.com/containerd/containerd/images/encryption"
-	encconfig "github.com/containerd/containerd/images/encryption/config"
-
-	"github.com/containerd/containerd/content"
-	"github.com/containerd/containerd/errdefs"
-	"github.com/containerd/containerd/leases"
-	"github.com/containerd/containerd/platforms"
-	digest "github.com/opencontainers/go-digest"
-	specs "github.com/opencontainers/image-spec/specs-go"
-	"github.com/pkg/errors"
-
-	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
-)
-
-// IsEncryptedDiff returns true if mediaType is a known encrypted media type.
-func IsEncryptedDiff(ctx context.Context, mediaType string) bool {
-	switch mediaType {
-	case MediaTypeDockerSchema2LayerGzipEnc, MediaTypeDockerSchema2LayerEnc:
-		return true
-	}
-	return false
-}
-
-// HasEncryptedLayer returns true if any LayerInfo indicates that the layer is encrypted
-func HasEncryptedLayer(ctx context.Context, layerInfos []ocispec.Descriptor) bool {
-	for i := 0; i < len(layerInfos); i++ {
-		if IsEncryptedDiff(ctx, layerInfos[i].MediaType) {
-			return true
-		}
-	}
-	return false
-}
-
-// encryptLayer encrypts the layer using the CryptoConfig and creates a new OCI Descriptor.
-// A call to this function may also only manipulate the wrapped keys list.
-// The caller is expected to store the returned encrypted data and OCI Descriptor
-func encryptLayer(cc *encconfig.CryptoConfig, dataReader content.ReaderAt, desc ocispec.Descriptor) (ocispec.Descriptor, io.Reader, error) {
-	var (
-		size int64
-		d    digest.Digest
-		err  error
-	)
-
-	encLayerReader, annotations, err := encryption.EncryptLayer(cc.EncryptConfig, encryption.ReaderFromReaderAt(dataReader), desc)
-	if err != nil {
-		return ocispec.Descriptor{}, nil, err
-	}
-
-	// were data touched ?
-	if encLayerReader != nil {
-		size = 0
-		d = ""
-	} else {
-		size = desc.Size
-		d = desc.Digest
-	}
-
-	newDesc := ocispec.Descriptor{
-		Digest:      d,
-		Size:        size,
-		Platform:    desc.Platform,
-		Annotations: annotations,
-	}
-
-	switch desc.MediaType {
-	case MediaTypeDockerSchema2LayerGzip:
-		newDesc.MediaType = MediaTypeDockerSchema2LayerGzipEnc
-	case MediaTypeDockerSchema2Layer:
-		newDesc.MediaType = MediaTypeDockerSchema2LayerEnc
-	case MediaTypeDockerSchema2LayerGzipEnc:
-		newDesc.MediaType = MediaTypeDockerSchema2LayerGzipEnc
-	case MediaTypeDockerSchema2LayerEnc:
-		newDesc.MediaType = MediaTypeDockerSchema2LayerEnc
-
-		// TODO: Mediatypes to be added in ocispec
-	case ocispec.MediaTypeImageLayerGzip:
-		newDesc.MediaType = MediaTypeDockerSchema2LayerGzipEnc
-	case ocispec.MediaTypeImageLayer:
-		newDesc.MediaType = MediaTypeDockerSchema2LayerEnc
-
-	default:
-		return ocispec.Descriptor{}, nil, errors.Errorf("Encryption: unsupporter layer MediaType: %s\n", desc.MediaType)
-	}
-
-	return newDesc, encLayerReader, nil
-}
-
-// decryptLayer decrypts the layer using the CryptoConfig and creates a new OCI Descriptor.
-// The caller is expected to store the returned plain data and OCI Descriptor
-func decryptLayer(cc *encconfig.CryptoConfig, dataReader content.ReaderAt, desc ocispec.Descriptor, unwrapOnly bool) (ocispec.Descriptor, io.Reader, error) {
-	resultReader, d, err := encryption.DecryptLayer(cc.DecryptConfig, encryption.ReaderFromReaderAt(dataReader), desc, unwrapOnly)
-	if err != nil || unwrapOnly {
-		return ocispec.Descriptor{}, nil, err
-	}
-
-	newDesc := ocispec.Descriptor{
-		Digest:   d,
-		Size:     0,
-		Platform: desc.Platform,
-	}
-
-	switch desc.MediaType {
-	case MediaTypeDockerSchema2LayerGzipEnc:
-		newDesc.MediaType = MediaTypeDockerSchema2LayerGzip
-	case MediaTypeDockerSchema2LayerEnc:
-		newDesc.MediaType = MediaTypeDockerSchema2Layer
-	default:
-		return ocispec.Descriptor{}, nil, errors.Errorf("Decryption: unsupporter layer MediaType: %s\n", desc.MediaType)
-	}
-	return newDesc, resultReader, nil
-}
-
-// cryptLayer handles the changes due to encryption or decryption of a layer
-func cryptLayer(ctx context.Context, cs content.Store, ls leases.Manager, l leases.Lease, desc ocispec.Descriptor, cc *encconfig.CryptoConfig, cryptoOp cryptoOp) (ocispec.Descriptor, error) {
-	var (
-		resultReader io.Reader
-		newDesc      ocispec.Descriptor
-	)
-
-	dataReader, err := cs.ReaderAt(ctx, desc)
-	if err != nil {
-		return ocispec.Descriptor{}, err
-	}
-	defer dataReader.Close()
-
-	if cryptoOp == cryptoOpEncrypt {
-		newDesc, resultReader, err = encryptLayer(cc, dataReader, desc)
-	} else {
-		newDesc, resultReader, err = decryptLayer(cc, dataReader, desc, cryptoOp == cryptoOpUnwrapOnly)
-	}
-	if err != nil || cryptoOp == cryptoOpUnwrapOnly {
-		return ocispec.Descriptor{}, err
-	}
-	// some operations, such as changing recipients, may not touch the layer at all
-	if resultReader != nil {
-		if ls == nil {
-			return ocispec.Descriptor{}, errors.New("Unexpected write to object without lease")
-		}
-
-		var rsrc leases.Resource
-		var ref string
-
-		// If we have the digest, write blob with checks
-		haveDigest := newDesc.Digest.String() != ""
-		if haveDigest {
-			ref = fmt.Sprintf("layer-%s", newDesc.Digest.String())
-			rsrc = leases.Resource{
-				ID:   newDesc.Digest.String(),
-				Type: "content",
-			}
-		} else {
-			ref = fmt.Sprintf("blob-%d-%d", rand.Int(), rand.Int())
-			rsrc = leases.Resource{
-				ID:   ref,
-				Type: "ingests",
-			}
-
-		}
-
-		// Add resource to lease and write blob
-		if err := ls.AddResource(ctx, l, rsrc); err != nil {
-			return ocispec.Descriptor{}, errors.Wrap(err, "Unable to add resource to lease")
-		}
-
-		if haveDigest {
-			if err := content.WriteBlob(ctx, cs, ref, resultReader, newDesc); err != nil {
-				return ocispec.Descriptor{}, errors.Wrap(err, "failed to write config")
-			}
-		} else {
-			newDesc.Digest, newDesc.Size, err = content.WriteBlobBlind(ctx, cs, ref, resultReader)
-			if err != nil {
-				return ocispec.Descriptor{}, err
-			}
-		}
-	}
-	return newDesc, err
-}
-
-// isDecriptorALayer determines whether the given Descriptor describes an image layer
-func isDescriptorALayer(desc ocispec.Descriptor) bool {
-	switch desc.MediaType {
-	case MediaTypeDockerSchema2LayerGzip, MediaTypeDockerSchema2Layer,
-		ocispec.MediaTypeImageLayerGzip, ocispec.MediaTypeImageLayer,
-		MediaTypeDockerSchema2LayerGzipEnc, MediaTypeDockerSchema2LayerEnc:
-		return true
-	}
-	return false
-}
-
-// Encrypt or decrypt all the Children of a given descriptor
-func cryptChildren(ctx context.Context, cs content.Store, ls leases.Manager, l leases.Lease, desc ocispec.Descriptor, cc *encconfig.CryptoConfig, lf LayerFilter, cryptoOp cryptoOp, thisPlatform *ocispec.Platform) (ocispec.Descriptor, bool, error) {
-	children, err := Children(ctx, cs, desc)
-	if err != nil {
-		if errdefs.IsNotFound(err) {
-			return desc, false, nil
-		}
-		return ocispec.Descriptor{}, false, err
-	}
-
-	var newLayers []ocispec.Descriptor
-	var config ocispec.Descriptor
-	modified := false
-
-	for _, child := range children {
-		// we only encrypt child layers and have to update their parents if encryption happened
-		switch child.MediaType {
-		case MediaTypeDockerSchema2Config, ocispec.MediaTypeImageConfig:
-			config = child
-		case MediaTypeDockerSchema2LayerGzip, MediaTypeDockerSchema2Layer,
-			ocispec.MediaTypeImageLayerGzip, ocispec.MediaTypeImageLayer:
-			if cryptoOp == cryptoOpEncrypt && lf(child) {
-				nl, err := cryptLayer(ctx, cs, ls, l, child, cc, cryptoOp)
-				if err != nil {
-					return ocispec.Descriptor{}, false, err
-				}
-				modified = true
-				newLayers = append(newLayers, nl)
-			} else {
-				newLayers = append(newLayers, child)
-			}
-		case MediaTypeDockerSchema2LayerGzipEnc, MediaTypeDockerSchema2LayerEnc:
-			// this one can be decrypted but also its recipients list changed
-			if lf(child) {
-				nl, err := cryptLayer(ctx, cs, ls, l, child, cc, cryptoOp)
-				if err != nil || cryptoOp == cryptoOpUnwrapOnly {
-					return ocispec.Descriptor{}, false, err
-				}
-				modified = true
-				newLayers = append(newLayers, nl)
-			} else {
-				newLayers = append(newLayers, child)
-			}
-		case MediaTypeDockerSchema2LayerForeign, MediaTypeDockerSchema2LayerForeignGzip:
-			// never encrypt/decrypt
-			newLayers = append(newLayers, child)
-		default:
-			return ocispec.Descriptor{}, false, errors.Errorf("bad/unhandled MediaType %s in encryptChildren\n", child.MediaType)
-		}
-	}
-
-	if modified && len(newLayers) > 0 {
-		newManifest := ocispec.Manifest{
-			Versioned: specs.Versioned{
-				SchemaVersion: 2,
-			},
-			Config: config,
-			Layers: newLayers,
-		}
-
-		mb, err := json.MarshalIndent(newManifest, "", "   ")
-		if err != nil {
-			return ocispec.Descriptor{}, false, errors.Wrap(err, "failed to marshal image")
-		}
-
-		newDesc := ocispec.Descriptor{
-			MediaType: ocispec.MediaTypeImageManifest,
-			Size:      int64(len(mb)),
-			Digest:    digest.Canonical.FromBytes(mb),
-			Platform:  desc.Platform,
-		}
-
-		labels := map[string]string{}
-		labels["containerd.io/gc.ref.content.0"] = newManifest.Config.Digest.String()
-		for i, ch := range newManifest.Layers {
-			labels[fmt.Sprintf("containerd.io/gc.ref.content.%d", i+1)] = ch.Digest.String()
-		}
-
-		ref := fmt.Sprintf("manifest-%s", newDesc.Digest.String())
-
-		if ls == nil {
-			return ocispec.Descriptor{}, false, errors.New("Unexpected write to object without lease")
-		}
-
-		rsrc := leases.Resource{
-			ID:   desc.Digest.String(),
-			Type: "content",
-		}
-
-		if err := ls.AddResource(ctx, l, rsrc); err != nil {
-			return ocispec.Descriptor{}, false, errors.Wrap(err, "Unable to add resource to lease")
-		}
-
-		if err := content.WriteBlob(ctx, cs, ref, bytes.NewReader(mb), newDesc, content.WithLabels(labels)); err != nil {
-			return ocispec.Descriptor{}, false, errors.Wrap(err, "failed to write config")
-		}
-		return newDesc, true, nil
-	}
-
-	return desc, modified, nil
-}
-
-// cryptManifest encrypts or decrypts the children of a top level manifest
-func cryptManifest(ctx context.Context, cs content.Store, ls leases.Manager, l leases.Lease, desc ocispec.Descriptor, cc *encconfig.CryptoConfig, lf LayerFilter, cryptoOp cryptoOp) (ocispec.Descriptor, bool, error) {
-	p, err := content.ReadBlob(ctx, cs, desc)
-	if err != nil {
-		return ocispec.Descriptor{}, false, err
-	}
-	var manifest ocispec.Manifest
-	if err := json.Unmarshal(p, &manifest); err != nil {
-		return ocispec.Descriptor{}, false, err
-	}
-	platform := platforms.DefaultSpec()
-	newDesc, modified, err := cryptChildren(ctx, cs, ls, l, desc, cc, lf, cryptoOp, &platform)
-	if err != nil || cryptoOp == cryptoOpUnwrapOnly {
-		return ocispec.Descriptor{}, false, err
-	}
-	return newDesc, modified, nil
-}
-
-// cryptManifestList encrypts or decrypts the children of a top level manifest list
-func cryptManifestList(ctx context.Context, cs content.Store, ls leases.Manager, l leases.Lease, desc ocispec.Descriptor, cc *encconfig.CryptoConfig, lf LayerFilter, cryptoOp cryptoOp) (ocispec.Descriptor, bool, error) {
-	// read the index; if any layer is encrypted and any manifests change we will need to rewrite it
-	b, err := content.ReadBlob(ctx, cs, desc)
-	if err != nil {
-		return ocispec.Descriptor{}, false, err
-	}
-
-	var index ocispec.Index
-	if err := json.Unmarshal(b, &index); err != nil {
-		return ocispec.Descriptor{}, false, err
-	}
-
-	var newManifests []ocispec.Descriptor
-	modified := false
-	for _, manifest := range index.Manifests {
-		newManifest, m, err := cryptChildren(ctx, cs, ls, l, manifest, cc, lf, cryptoOp, manifest.Platform)
-		if err != nil || cryptoOp == cryptoOpUnwrapOnly {
-			return ocispec.Descriptor{}, false, err
-		}
-		if m {
-			modified = true
-		}
-		newManifests = append(newManifests, newManifest)
-	}
-
-	if modified {
-		// we need to update the index
-		newIndex := ocispec.Index{
-			Versioned: index.Versioned,
-			Manifests: newManifests,
-		}
-
-		mb, err := json.MarshalIndent(newIndex, "", "   ")
-		if err != nil {
-			return ocispec.Descriptor{}, false, errors.Wrap(err, "failed to marshal index")
-		}
-
-		newDesc := ocispec.Descriptor{
-			MediaType: ocispec.MediaTypeImageIndex,
-			Size:      int64(len(mb)),
-			Digest:    digest.Canonical.FromBytes(mb),
-		}
-
-		labels := map[string]string{}
-		for i, m := range newIndex.Manifests {
-			labels[fmt.Sprintf("containerd.io/gc.ref.content.%d", i)] = m.Digest.String()
-		}
-
-		ref := fmt.Sprintf("index-%s", newDesc.Digest.String())
-
-		if ls == nil {
-			return ocispec.Descriptor{}, false, errors.New("Unexpected write to object without lease")
-		}
-
-		rsrc := leases.Resource{
-			ID:   desc.Digest.String(),
-			Type: "content",
-		}
-
-		if err := ls.AddResource(ctx, l, rsrc); err != nil {
-			return ocispec.Descriptor{}, false, errors.Wrap(err, "Unable to add resource to lease")
-		}
-
-		if err = content.WriteBlob(ctx, cs, ref, bytes.NewReader(mb), newDesc, content.WithLabels(labels)); err != nil {
-			return ocispec.Descriptor{}, false, errors.Wrap(err, "failed to write index")
-		}
-		return newDesc, true, nil
-	}
-
-	return desc, false, nil
-}
-
-// cryptImage is the dispatcher to encrypt/decrypt an image; it accepts either an OCI descriptor
-// representing a manifest list or a single manifest
-func cryptImage(ctx context.Context, cs content.Store, ls leases.Manager, l leases.Lease, desc ocispec.Descriptor, cc *encconfig.CryptoConfig, lf LayerFilter, cryptoOp cryptoOp) (ocispec.Descriptor, bool, error) {
-	if cc == nil {
-		return ocispec.Descriptor{}, false, errors.Wrapf(errdefs.ErrInvalidArgument, "CryptoConfig must not be nil")
-	}
-	switch desc.MediaType {
-	case ocispec.MediaTypeImageIndex, MediaTypeDockerSchema2ManifestList:
-		return cryptManifestList(ctx, cs, ls, l, desc, cc, lf, cryptoOp)
-	case ocispec.MediaTypeImageManifest, MediaTypeDockerSchema2Manifest:
-		return cryptManifest(ctx, cs, ls, l, desc, cc, lf, cryptoOp)
-	default:
-		return ocispec.Descriptor{}, false, errors.Errorf("CryptImage: Unhandled media type: %s", desc.MediaType)
-	}
-}
-
-// EncryptImage encrypts an image; it accepts either an OCI descriptor representing a manifest list or a single manifest
-func EncryptImage(ctx context.Context, cs content.Store, ls leases.Manager, l leases.Lease, desc ocispec.Descriptor, cc *encconfig.CryptoConfig, lf LayerFilter) (ocispec.Descriptor, bool, error) {
-	return cryptImage(ctx, cs, ls, l, desc, cc, lf, cryptoOpEncrypt)
-}
-
-// DecryptImage decrypts an image; it accepts either an OCI descriptor representing a manifest list or a single manifest
-func DecryptImage(ctx context.Context, cs content.Store, ls leases.Manager, l leases.Lease, desc ocispec.Descriptor, cc *encconfig.CryptoConfig, lf LayerFilter) (ocispec.Descriptor, bool, error) {
-	return cryptImage(ctx, cs, ls, l, desc, cc, lf, cryptoOpDecrypt)
-}
-
-// CheckAuthorization checks whether a user has the right keys to be allowed to access an image (every layer)
-// It takes decrypting of the layers only as far as decrypting the asymmetrically encrypted data
-// The decryption is only done for the current platform
-func CheckAuthorization(ctx context.Context, cs content.Store, desc ocispec.Descriptor, dc *encconfig.DecryptConfig) error {
-	cc := encconfig.CryptoConfig{
-		DecryptConfig: dc,
-	}
-	lf := func(desc ocispec.Descriptor) bool {
-		return true
-	}
-	// We shouldn't need to create any objects in CheckAuthorization, so no lease required.
-	_, _, err := cryptImage(ctx, cs, nil, leases.Lease{}, desc, &cc, lf, cryptoOpUnwrapOnly)
-	if err != nil {
-		return errors.Wrapf(err, "you are not authorized to use this image")
-	}
-	return nil
-}

images/encryption/encryption.go

@@ -17,228 +17,461 @@
 package encryption
 
 import (
-	"encoding/base64"
+	"bytes"
+	"context"
 	"encoding/json"
+	"fmt"
 	"io"
-	"strings"
+	"math/rand"
 
+	"github.com/containerd/containerd/images"
+	"github.com/containerd/containerd/pkg/encryption"
+	encconfig "github.com/containerd/containerd/pkg/encryption/config"
+
+	"github.com/containerd/containerd/content"
 	"github.com/containerd/containerd/errdefs"
-	"github.com/containerd/containerd/images/encryption/blockcipher"
-	"github.com/containerd/containerd/images/encryption/config"
-	"github.com/containerd/containerd/images/encryption/keywrap"
-	"github.com/containerd/containerd/images/encryption/keywrap/jwe"
-	"github.com/containerd/containerd/images/encryption/keywrap/pgp"
-	"github.com/containerd/containerd/images/encryption/keywrap/pkcs7"
-	"github.com/opencontainers/go-digest"
-	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
+	"github.com/containerd/containerd/leases"
+	"github.com/containerd/containerd/platforms"
+	digest "github.com/opencontainers/go-digest"
+	specs "github.com/opencontainers/image-spec/specs-go"
 	"github.com/pkg/errors"
+
+	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 )
 
-func init() {
-	keyWrappers = make(map[string]keywrap.KeyWrapper)
-	keyWrapperAnnotations = make(map[string]string)
-	RegisterKeyWrapper("pgp", pgp.NewKeyWrapper())
-	RegisterKeyWrapper("jwe", jwe.NewKeyWrapper())
-	RegisterKeyWrapper("pkcs7", pkcs7.NewKeyWrapper())
+type cryptoOp int
+
+const (
+	cryptoOpEncrypt    cryptoOp = iota
+	cryptoOpDecrypt             = iota
+	cryptoOpUnwrapOnly          = iota
+)
+
+// LayerFilter allows to select Layers by certain criteria
+type LayerFilter func(desc ocispec.Descriptor) bool
+
+// IsEncryptedDiff returns true if mediaType is a known encrypted media type.
+func IsEncryptedDiff(ctx context.Context, mediaType string) bool {
+	switch mediaType {
+	case images.MediaTypeDockerSchema2LayerGzipEnc, images.MediaTypeDockerSchema2LayerEnc:
+		return true
+	}
+	return false
 }
 
-var keyWrappers map[string]keywrap.KeyWrapper
-var keyWrapperAnnotations map[string]string
-
-// RegisterKeyWrapper allows to register key wrappers by their encryption scheme
-func RegisterKeyWrapper(scheme string, iface keywrap.KeyWrapper) {
-	keyWrappers[scheme] = iface
-	keyWrapperAnnotations[iface.GetAnnotationID()] = scheme
-}
-
-// GetKeyWrapper looks up the encryptor interface given an encryption scheme (gpg, jwe)
-func GetKeyWrapper(scheme string) keywrap.KeyWrapper {
-	return keyWrappers[scheme]
-}
-
-// GetWrappedKeysMap returns a map of wrappedKeys as values in a
-// map with the encryption scheme(s) as the key(s)
-func GetWrappedKeysMap(desc ocispec.Descriptor) map[string]string {
-	wrappedKeysMap := make(map[string]string)
-
-	for annotationsID, scheme := range keyWrapperAnnotations {
-		if annotation, ok := desc.Annotations[annotationsID]; ok {
-			wrappedKeysMap[scheme] = annotation
+// HasEncryptedLayer returns true if any LayerInfo indicates that the layer is encrypted
+func HasEncryptedLayer(ctx context.Context, layerInfos []ocispec.Descriptor) bool {
+	for i := 0; i < len(layerInfos); i++ {
+		if IsEncryptedDiff(ctx, layerInfos[i].MediaType) {
+			return true
 		}
 	}
-	return wrappedKeysMap
+	return false
 }
 
-// EncryptLayer encrypts the layer by running one encryptor after the other
-func EncryptLayer(ec *config.EncryptConfig, encOrPlainLayerReader io.Reader, desc ocispec.Descriptor) (io.Reader, map[string]string, error) {
+// encryptLayer encrypts the layer using the CryptoConfig and creates a new OCI Descriptor.
+// A call to this function may also only manipulate the wrapped keys list.
+// The caller is expected to store the returned encrypted data and OCI Descriptor
+func encryptLayer(cc *encconfig.CryptoConfig, dataReader content.ReaderAt, desc ocispec.Descriptor) (ocispec.Descriptor, io.Reader, error) {
 	var (
-		encLayerReader io.Reader
-		err            error
-		optsData       []byte
+		size int64
+		d    digest.Digest
+		err  error
 	)
 
-	if ec == nil {
-		return nil, nil, errors.Wrapf(errdefs.ErrInvalidArgument, "EncryptConfig must not be nil")
+	encLayerReader, annotations, err := encryption.EncryptLayer(cc.EncryptConfig, encryption.ReaderFromReaderAt(dataReader), desc)
+	if err != nil {
+		return ocispec.Descriptor{}, nil, err
 	}
 
-	for annotationsID := range keyWrapperAnnotations {
-		annotation := desc.Annotations[annotationsID]
-		if annotation != "" {
-			optsData, err = decryptLayerKeyOptsData(&ec.DecryptConfig, desc)
-			if err != nil {
-				return nil, nil, err
-			}
-			// already encrypted!
-		}
+	// were data touched ?
+	if encLayerReader != nil {
+		size = 0
+		d = ""
+	} else {
+		size = desc.Size
+		d = desc.Digest
 	}
 
-	newAnnotations := make(map[string]string)
+	newDesc := ocispec.Descriptor{
+		Digest:      d,
+		Size:        size,
+		Platform:    desc.Platform,
+		Annotations: annotations,
+	}
 
-	for annotationsID, scheme := range keyWrapperAnnotations {
-		b64Annotations := desc.Annotations[annotationsID]
-		if b64Annotations == "" && optsData == nil {
-			encLayerReader, optsData, err = commonEncryptLayer(encOrPlainLayerReader, desc.Digest, blockcipher.AESSIVCMAC512)
-			if err != nil {
-				return nil, nil, err
-			}
-		}
-		keywrapper := GetKeyWrapper(scheme)
-		b64Annotations, err = preWrapKeys(keywrapper, ec, b64Annotations, optsData)
-		if err != nil {
-			return nil, nil, err
-		}
-		if b64Annotations != "" {
-			newAnnotations[annotationsID] = b64Annotations
-		}
+	switch desc.MediaType {
+	case images.MediaTypeDockerSchema2LayerGzip:
+		newDesc.MediaType = images.MediaTypeDockerSchema2LayerGzipEnc
+	case images.MediaTypeDockerSchema2Layer:
+		newDesc.MediaType = images.MediaTypeDockerSchema2LayerEnc
+	case images.MediaTypeDockerSchema2LayerGzipEnc:
+		newDesc.MediaType = images.MediaTypeDockerSchema2LayerGzipEnc
+	case images.MediaTypeDockerSchema2LayerEnc:
+		newDesc.MediaType = images.MediaTypeDockerSchema2LayerEnc
+
+	// TODO: Mediatypes to be added in ocispec
+	case ocispec.MediaTypeImageLayerGzip:
+		newDesc.MediaType = images.MediaTypeDockerSchema2LayerGzipEnc
+	case ocispec.MediaTypeImageLayer:
+		newDesc.MediaType = images.MediaTypeDockerSchema2LayerEnc
+
+	default:
+		return ocispec.Descriptor{}, nil, errors.Errorf("Encryption: unsupporter layer MediaType: %s\n", desc.MediaType)
 	}
-	if len(newAnnotations) == 0 {
-		err = errors.Errorf("no encryptor found to handle encryption")
-	}
-	// if nothing was encrypted, we just return encLayer = nil
-	return encLayerReader, newAnnotations, err
+
+	return newDesc, encLayerReader, nil
 }
 
-// preWrapKeys calls WrapKeys and handles the base64 encoding and concatenation of the
-// annotation data
-func preWrapKeys(keywrapper keywrap.KeyWrapper, ec *config.EncryptConfig, b64Annotations string, optsData []byte) (string, error) {
-	newAnnotation, err := keywrapper.WrapKeys(ec, optsData)
-	if err != nil || len(newAnnotation) == 0 {
-		return b64Annotations, err
-	}
-	b64newAnnotation := base64.StdEncoding.EncodeToString(newAnnotation)
-	if b64Annotations == "" {
-		return b64newAnnotation, nil
-	}
-	return b64Annotations + "," + b64newAnnotation, nil
-}
-
-// DecryptLayer decrypts a layer trying one keywrap.KeyWrapper after the other to see whether it
-// can apply the provided private key
-// If unwrapOnly is set we will only try to decrypt the layer encryption key and return
-func DecryptLayer(dc *config.DecryptConfig, encLayerReader io.Reader, desc ocispec.Descriptor, unwrapOnly bool) (io.Reader, digest.Digest, error) {
-	if dc == nil {
-		return nil, "", errors.Wrapf(errdefs.ErrInvalidArgument, "DecryptConfig must not be nil")
-	}
-	optsData, err := decryptLayerKeyOptsData(dc, desc)
+// decryptLayer decrypts the layer using the CryptoConfig and creates a new OCI Descriptor.
+// The caller is expected to store the returned plain data and OCI Descriptor
+func decryptLayer(cc *encconfig.CryptoConfig, dataReader content.ReaderAt, desc ocispec.Descriptor, unwrapOnly bool) (ocispec.Descriptor, io.Reader, error) {
+	resultReader, d, err := encryption.DecryptLayer(cc.DecryptConfig, encryption.ReaderFromReaderAt(dataReader), desc, unwrapOnly)
 	if err != nil || unwrapOnly {
-		return nil, "", err
+		return ocispec.Descriptor{}, nil, err
 	}
 
-	return commonDecryptLayer(encLayerReader, optsData)
+	newDesc := ocispec.Descriptor{
+		Digest:   d,
+		Size:     0,
+		Platform: desc.Platform,
+	}
+
+	switch desc.MediaType {
+	case images.MediaTypeDockerSchema2LayerGzipEnc:
+		newDesc.MediaType = images.MediaTypeDockerSchema2LayerGzip
+	case images.MediaTypeDockerSchema2LayerEnc:
+		newDesc.MediaType = images.MediaTypeDockerSchema2Layer
+	default:
+		return ocispec.Descriptor{}, nil, errors.Errorf("Decryption: unsupporter layer MediaType: %s\n", desc.MediaType)
+	}
+	return newDesc, resultReader, nil
 }
 
-func decryptLayerKeyOptsData(dc *config.DecryptConfig, desc ocispec.Descriptor) ([]byte, error) {
-	privKeyGiven := false
-	for annotationsID, scheme := range keyWrapperAnnotations {
-		b64Annotation := desc.Annotations[annotationsID]
-		if b64Annotation != "" {
-			keywrapper := GetKeyWrapper(scheme)
+// cryptLayer handles the changes due to encryption or decryption of a layer
+func cryptLayer(ctx context.Context, cs content.Store, ls leases.Manager, l leases.Lease, desc ocispec.Descriptor, cc *encconfig.CryptoConfig, cryptoOp cryptoOp) (ocispec.Descriptor, error) {
+	var (
+		resultReader io.Reader
+		newDesc      ocispec.Descriptor
+	)
 
-			if len(keywrapper.GetPrivateKeys(dc.Parameters)) == 0 {
-				continue
+	dataReader, err := cs.ReaderAt(ctx, desc)
+	if err != nil {
+		return ocispec.Descriptor{}, err
+	}
+	defer dataReader.Close()
+
+	if cryptoOp == cryptoOpEncrypt {
+		newDesc, resultReader, err = encryptLayer(cc, dataReader, desc)
+	} else {
+		newDesc, resultReader, err = decryptLayer(cc, dataReader, desc, cryptoOp == cryptoOpUnwrapOnly)
+	}
+	if err != nil || cryptoOp == cryptoOpUnwrapOnly {
+		return ocispec.Descriptor{}, err
+	}
+	// some operations, such as changing recipients, may not touch the layer at all
+	if resultReader != nil {
+		if ls == nil {
+			return ocispec.Descriptor{}, errors.New("Unexpected write to object without lease")
+		}
+
+		var rsrc leases.Resource
+		var ref string
+
+		// If we have the digest, write blob with checks
+		haveDigest := newDesc.Digest.String() != ""
+		if haveDigest {
+			ref = fmt.Sprintf("layer-%s", newDesc.Digest.String())
+			rsrc = leases.Resource{
+				ID:   newDesc.Digest.String(),
+				Type: "content",
+			}
+		} else {
+			ref = fmt.Sprintf("blob-%d-%d", rand.Int(), rand.Int())
+			rsrc = leases.Resource{
+				ID:   ref,
+				Type: "ingests",
 			}
-			privKeyGiven = true
 
-			optsData, err := preUnwrapKey(keywrapper, dc, b64Annotation)
+		}
+
+		// Add resource to lease and write blob
+		if err := ls.AddResource(ctx, l, rsrc); err != nil {
+			return ocispec.Descriptor{}, errors.Wrap(err, "Unable to add resource to lease")
+		}
+
+		if haveDigest {
+			if err := content.WriteBlob(ctx, cs, ref, resultReader, newDesc); err != nil {
+				return ocispec.Descriptor{}, errors.Wrap(err, "failed to write config")
+			}
+		} else {
+			newDesc.Digest, newDesc.Size, err = ingestReader(ctx, cs, ref, resultReader)
 			if err != nil {
-				// try next keywrap.KeyWrapper
-				continue
+				return ocispec.Descriptor{}, err
 			}
-			if optsData == nil {
-				// try next keywrap.KeyWrapper
-				continue
+		}
+	}
+	return newDesc, err
+}
+
+func ingestReader(ctx context.Context, cs content.Ingester, ref string, r io.Reader) (digest.Digest, int64, error) {
+	cw, err := content.OpenWriter(ctx, cs, content.WithRef(ref))
+	if err != nil {
+		return "", 0, errors.Wrap(err, "failed to open writer")
+	}
+	defer cw.Close()
+
+	if _, err := content.CopyReader(cw, r); err != nil {
+		return "", 0, errors.Wrap(err, "copy failed")
+	}
+
+	st, err := cw.Status()
+	if err != nil {
+		return "", 0, errors.Wrap(err, "failed to get state")
+	}
+
+	if err := cw.Commit(ctx, st.Offset, ""); err != nil {
+		if !errdefs.IsAlreadyExists(err) {
+			return "", 0, errors.Wrapf(err, "failed commit on ref %q", ref)
+		}
+	}
+
+	return cw.Digest(), st.Offset, nil
+}
+
+// Encrypt or decrypt all the Children of a given descriptor
+func cryptChildren(ctx context.Context, cs content.Store, ls leases.Manager, l leases.Lease, desc ocispec.Descriptor, cc *encconfig.CryptoConfig, lf LayerFilter, cryptoOp cryptoOp, thisPlatform *ocispec.Platform) (ocispec.Descriptor, bool, error) {
+	children, err := images.Children(ctx, cs, desc)
+	if err != nil {
+		if errdefs.IsNotFound(err) {
+			return desc, false, nil
+		}
+		return ocispec.Descriptor{}, false, err
+	}
+
+	var newLayers []ocispec.Descriptor
+	var config ocispec.Descriptor
+	modified := false
+
+	for _, child := range children {
+		// we only encrypt child layers and have to update their parents if encryption happened
+		switch child.MediaType {
+		case images.MediaTypeDockerSchema2Config, ocispec.MediaTypeImageConfig:
+			config = child
+		case images.MediaTypeDockerSchema2LayerGzip, images.MediaTypeDockerSchema2Layer,
+			ocispec.MediaTypeImageLayerGzip, ocispec.MediaTypeImageLayer:
+			if cryptoOp == cryptoOpEncrypt && lf(child) {
+				nl, err := cryptLayer(ctx, cs, ls, l, child, cc, cryptoOp)
+				if err != nil {
+					return ocispec.Descriptor{}, false, err
+				}
+				modified = true
+				newLayers = append(newLayers, nl)
+			} else {
+				newLayers = append(newLayers, child)
 			}
-			return optsData, nil
+		case images.MediaTypeDockerSchema2LayerGzipEnc, images.MediaTypeDockerSchema2LayerEnc:
+			// this one can be decrypted but also its recipients list changed
+			if lf(child) {
+				nl, err := cryptLayer(ctx, cs, ls, l, child, cc, cryptoOp)
+				if err != nil || cryptoOp == cryptoOpUnwrapOnly {
+					return ocispec.Descriptor{}, false, err
+				}
+				modified = true
+				newLayers = append(newLayers, nl)
+			} else {
+				newLayers = append(newLayers, child)
+			}
+		case images.MediaTypeDockerSchema2LayerForeign, images.MediaTypeDockerSchema2LayerForeignGzip:
+			// never encrypt/decrypt
+			newLayers = append(newLayers, child)
+		default:
+			return ocispec.Descriptor{}, false, errors.Errorf("bad/unhandled MediaType %s in encryptChildren\n", child.MediaType)
 		}
 	}
-	if !privKeyGiven {
-		return nil, errors.New("missing private key needed for decryption")
-	}
-	return nil, errors.Errorf("no suitable key unwrapper found or none of the private keys could be used for decryption")
-}
 
-// preUnwrapKey decodes the comma separated base64 strings and calls the Unwrap function
-// of the given keywrapper with it and returns the result in case the Unwrap functions
-// does not return an error. If all attempts fail, an error is returned.
-func preUnwrapKey(keywrapper keywrap.KeyWrapper, dc *config.DecryptConfig, b64Annotations string) ([]byte, error) {
-	if b64Annotations == "" {
-		return nil, nil
-	}
-	for _, b64Annotation := range strings.Split(b64Annotations, ",") {
-		annotation, err := base64.StdEncoding.DecodeString(b64Annotation)
+	if modified && len(newLayers) > 0 {
+		newManifest := ocispec.Manifest{
+			Versioned: specs.Versioned{
+				SchemaVersion: 2,
+			},
+			Config: config,
+			Layers: newLayers,
+		}
+
+		mb, err := json.MarshalIndent(newManifest, "", "   ")
 		if err != nil {
-			return nil, errors.New("could not base64 decode the annotation")
+			return ocispec.Descriptor{}, false, errors.Wrap(err, "failed to marshal image")
 		}
-		optsData, err := keywrapper.UnwrapKey(dc, annotation)
+
+		newDesc := ocispec.Descriptor{
+			MediaType: ocispec.MediaTypeImageManifest,
+			Size:      int64(len(mb)),
+			Digest:    digest.Canonical.FromBytes(mb),
+			Platform:  desc.Platform,
+		}
+
+		labels := map[string]string{}
+		labels["containerd.io/gc.ref.content.0"] = newManifest.Config.Digest.String()
+		for i, ch := range newManifest.Layers {
+			labels[fmt.Sprintf("containerd.io/gc.ref.content.%d", i+1)] = ch.Digest.String()
+		}
+
+		ref := fmt.Sprintf("manifest-%s", newDesc.Digest.String())
+
+		if ls == nil {
+			return ocispec.Descriptor{}, false, errors.New("Unexpected write to object without lease")
+		}
+
+		rsrc := leases.Resource{
+			ID:   desc.Digest.String(),
+			Type: "content",
+		}
+
+		if err := ls.AddResource(ctx, l, rsrc); err != nil {
+			return ocispec.Descriptor{}, false, errors.Wrap(err, "Unable to add resource to lease")
+		}
+
+		if err := content.WriteBlob(ctx, cs, ref, bytes.NewReader(mb), newDesc, content.WithLabels(labels)); err != nil {
+			return ocispec.Descriptor{}, false, errors.Wrap(err, "failed to write config")
+		}
+		return newDesc, true, nil
+	}
+
+	return desc, modified, nil
+}
+
+// cryptManifest encrypts or decrypts the children of a top level manifest
+func cryptManifest(ctx context.Context, cs content.Store, ls leases.Manager, l leases.Lease, desc ocispec.Descriptor, cc *encconfig.CryptoConfig, lf LayerFilter, cryptoOp cryptoOp) (ocispec.Descriptor, bool, error) {
+	p, err := content.ReadBlob(ctx, cs, desc)
+	if err != nil {
+		return ocispec.Descriptor{}, false, err
+	}
+	var manifest ocispec.Manifest
+	if err := json.Unmarshal(p, &manifest); err != nil {
+		return ocispec.Descriptor{}, false, err
+	}
+	platform := platforms.DefaultSpec()
+	newDesc, modified, err := cryptChildren(ctx, cs, ls, l, desc, cc, lf, cryptoOp, &platform)
+	if err != nil || cryptoOp == cryptoOpUnwrapOnly {
+		return ocispec.Descriptor{}, false, err
+	}
+	return newDesc, modified, nil
+}
+
+// cryptManifestList encrypts or decrypts the children of a top level manifest list
+func cryptManifestList(ctx context.Context, cs content.Store, ls leases.Manager, l leases.Lease, desc ocispec.Descriptor, cc *encconfig.CryptoConfig, lf LayerFilter, cryptoOp cryptoOp) (ocispec.Descriptor, bool, error) {
+	// read the index; if any layer is encrypted and any manifests change we will need to rewrite it
+	b, err := content.ReadBlob(ctx, cs, desc)
+	if err != nil {
+		return ocispec.Descriptor{}, false, err
+	}
+
+	var index ocispec.Index
+	if err := json.Unmarshal(b, &index); err != nil {
+		return ocispec.Descriptor{}, false, err
+	}
+
+	var newManifests []ocispec.Descriptor
+	modified := false
+	for _, manifest := range index.Manifests {
+		newManifest, m, err := cryptChildren(ctx, cs, ls, l, manifest, cc, lf, cryptoOp, manifest.Platform)
+		if err != nil || cryptoOp == cryptoOpUnwrapOnly {
+			return ocispec.Descriptor{}, false, err
+		}
+		if m {
+			modified = true
+		}
+		newManifests = append(newManifests, newManifest)
+	}
+
+	if modified {
+		// we need to update the index
+		newIndex := ocispec.Index{
+			Versioned: index.Versioned,
+			Manifests: newManifests,
+		}
+
+		mb, err := json.MarshalIndent(newIndex, "", "   ")
 		if err != nil {
-			continue
+			return ocispec.Descriptor{}, false, errors.Wrap(err, "failed to marshal index")
 		}
-		return optsData, nil
+
+		newDesc := ocispec.Descriptor{
+			MediaType: ocispec.MediaTypeImageIndex,
+			Size:      int64(len(mb)),
+			Digest:    digest.Canonical.FromBytes(mb),
+		}
+
+		labels := map[string]string{}
+		for i, m := range newIndex.Manifests {
+			labels[fmt.Sprintf("containerd.io/gc.ref.content.%d", i)] = m.Digest.String()
+		}
+
+		ref := fmt.Sprintf("index-%s", newDesc.Digest.String())
+
+		if ls == nil {
+			return ocispec.Descriptor{}, false, errors.New("Unexpected write to object without lease")
+		}
+
+		rsrc := leases.Resource{
+			ID:   desc.Digest.String(),
+			Type: "content",
+		}
+
+		if err := ls.AddResource(ctx, l, rsrc); err != nil {
+			return ocispec.Descriptor{}, false, errors.Wrap(err, "Unable to add resource to lease")
+		}
+
+		if err = content.WriteBlob(ctx, cs, ref, bytes.NewReader(mb), newDesc, content.WithLabels(labels)); err != nil {
+			return ocispec.Descriptor{}, false, errors.Wrap(err, "failed to write index")
+		}
+		return newDesc, true, nil
 	}
-	return nil, errors.New("no suitable key found for decrypting layer key")
+
+	return desc, false, nil
 }
 
-// commonEncryptLayer is a function to encrypt the plain layer using a new random
-// symmetric key and return the LayerBlockCipherHandler's JSON in string form for
-// later use during decryption
-func commonEncryptLayer(plainLayerReader io.Reader, d digest.Digest, typ blockcipher.LayerCipherType) (io.Reader, []byte, error) {
-	lbch, err := blockcipher.NewLayerBlockCipherHandler()
-	if err != nil {
-		return nil, nil, err
+// cryptImage is the dispatcher to encrypt/decrypt an image; it accepts either an OCI descriptor
+// representing a manifest list or a single manifest
+func cryptImage(ctx context.Context, cs content.Store, ls leases.Manager, l leases.Lease, desc ocispec.Descriptor, cc *encconfig.CryptoConfig, lf LayerFilter, cryptoOp cryptoOp) (ocispec.Descriptor, bool, error) {
+	if cc == nil {
+		return ocispec.Descriptor{}, false, errors.Wrapf(errdefs.ErrInvalidArgument, "CryptoConfig must not be nil")
 	}
-
-	encLayerReader, opts, err := lbch.Encrypt(plainLayerReader, typ)
-	if err != nil {
-		return nil, nil, err
+	switch desc.MediaType {
+	case ocispec.MediaTypeImageIndex, images.MediaTypeDockerSchema2ManifestList:
+		return cryptManifestList(ctx, cs, ls, l, desc, cc, lf, cryptoOp)
+	case ocispec.MediaTypeImageManifest, images.MediaTypeDockerSchema2Manifest:
+		return cryptManifest(ctx, cs, ls, l, desc, cc, lf, cryptoOp)
+	default:
+		return ocispec.Descriptor{}, false, errors.Errorf("CryptImage: Unhandled media type: %s", desc.MediaType)
 	}
-	opts.Digest = d
-
-	optsData, err := json.Marshal(opts)
-	if err != nil {
-		return nil, nil, errors.Wrapf(err, "could not JSON marshal opts")
-	}
-
-	return encLayerReader, optsData, err
 }
 
-// commonDecryptLayer decrypts an encrypted layer previously encrypted with commonEncryptLayer
-// by passing along the optsData
-func commonDecryptLayer(encLayerReader io.Reader, optsData []byte) (io.Reader, digest.Digest, error) {
-	opts := blockcipher.LayerBlockCipherOptions{}
-	err := json.Unmarshal(optsData, &opts)
-	if err != nil {
-		return nil, "", errors.Wrapf(err, "could not JSON unmarshal optsData")
-	}
-
-	lbch, err := blockcipher.NewLayerBlockCipherHandler()
-	if err != nil {
-		return nil, "", err
-	}
-
-	plainLayerReader, opts, err := lbch.Decrypt(encLayerReader, opts)
-	if err != nil {
-		return nil, "", err
-	}
-
-	return plainLayerReader, opts.Digest, nil
+// EncryptImage encrypts an image; it accepts either an OCI descriptor representing a manifest list or a single manifest
+func EncryptImage(ctx context.Context, cs content.Store, ls leases.Manager, l leases.Lease, desc ocispec.Descriptor, cc *encconfig.CryptoConfig, lf LayerFilter) (ocispec.Descriptor, bool, error) {
+	return cryptImage(ctx, cs, ls, l, desc, cc, lf, cryptoOpEncrypt)
+}
+
+// DecryptImage decrypts an image; it accepts either an OCI descriptor representing a manifest list or a single manifest
+func DecryptImage(ctx context.Context, cs content.Store, ls leases.Manager, l leases.Lease, desc ocispec.Descriptor, cc *encconfig.CryptoConfig, lf LayerFilter) (ocispec.Descriptor, bool, error) {
+	return cryptImage(ctx, cs, ls, l, desc, cc, lf, cryptoOpDecrypt)
+}
+
+// CheckAuthorization checks whether a user has the right keys to be allowed to access an image (every layer)
+// It takes decrypting of the layers only as far as decrypting the asymmetrically encrypted data
+// The decryption is only done for the current platform
+func CheckAuthorization(ctx context.Context, cs content.Store, desc ocispec.Descriptor, dc *encconfig.DecryptConfig) error {
+	cc := encconfig.CryptoConfig{
+		DecryptConfig: dc,
+	}
+	lf := func(desc ocispec.Descriptor) bool {
+		return true
+	}
+	// We shouldn't need to create any objects in CheckAuthorization, so no lease required.
+	_, _, err := cryptImage(ctx, cs, nil, leases.Lease{}, desc, &cc, lf, cryptoOpUnwrapOnly)
+	if err != nil {
+		return errors.Wrapf(err, "you are not authorized to use this image")
+	}
+	return nil
 }

images/image.go

@@ -64,9 +64,6 @@ type DeleteOptions struct {
 // DeleteOpt allows configuring a delete operation
 type DeleteOpt func(context.Context, *DeleteOptions) error
 
-// LayerFilter allows to select Layers by certain criteria
-type LayerFilter func(desc ocispec.Descriptor) bool
-
 // SynchronousDelete is used to indicate that an image deletion and removal of
 // the image resources should occur synchronously before returning a result.
 func SynchronousDelete() DeleteOpt {
@@ -89,14 +86,6 @@ type Store interface {
 	Delete(ctx context.Context, name string, opts ...DeleteOpt) error
 }
 
-type cryptoOp int
-
-const (
-	cryptoOpEncrypt    cryptoOp = iota
-	cryptoOpDecrypt             = iota
-	cryptoOpUnwrapOnly          = iota
-)
-
 // TODO(stevvooe): Many of these functions make strong platform assumptions,
 // which are untrue in a lot of cases. More refactoring must be done here to
 // make this work in all cases.
@@ -408,7 +397,7 @@ func RootFS(ctx context.Context, provider content.Provider, configDesc ocispec.D
 func IsCompressedDiff(ctx context.Context, mediaType string) (bool, error) {
 	switch mediaType {
 	case ocispec.MediaTypeImageLayer, MediaTypeDockerSchema2Layer:
-	case ocispec.MediaTypeImageLayerGzip, MediaTypeDockerSchema2LayerGzip, MediaTypeDockerSchema2LayerGzipEnc:
+	case ocispec.MediaTypeImageLayerGzip, MediaTypeDockerSchema2LayerGzip:
 		return true, nil
 	default:
 		// Still apply all generic media types *.tar[.+]gzip and *.tar
@@ -447,13 +436,17 @@ func GetImageLayerDescriptors(ctx context.Context, cs content.Store, desc ocispe
 		for _, child := range children {
 			var tmp []ocispec.Descriptor
 
-			if isDescriptorALayer(child) {
+			switch child.MediaType {
+			case MediaTypeDockerSchema2LayerGzip, MediaTypeDockerSchema2Layer,
+				ocispec.MediaTypeImageLayerGzip, ocispec.MediaTypeImageLayer,
+				MediaTypeDockerSchema2LayerGzipEnc, MediaTypeDockerSchema2LayerEnc:
 				tdesc := child
 				tdesc.Platform = platform
 				tmp = append(tmp, tdesc)
-			} else {
+			default:
 				tmp, err = GetImageLayerDescriptors(ctx, cs, child)
 			}
+
 			if err != nil {
 				return []ocispec.Descriptor{}, err
 			}

pkg/encryption/encryption.go

@@ -0,0 +1,244 @@
+/*
+   Copyright The containerd Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package encryption
+
+import (
+	"encoding/base64"
+	"encoding/json"
+	"io"
+	"strings"
+
+	"github.com/containerd/containerd/errdefs"
+	"github.com/containerd/containerd/pkg/encryption/blockcipher"
+	"github.com/containerd/containerd/pkg/encryption/config"
+	"github.com/containerd/containerd/pkg/encryption/keywrap"
+	"github.com/containerd/containerd/pkg/encryption/keywrap/jwe"
+	"github.com/containerd/containerd/pkg/encryption/keywrap/pgp"
+	"github.com/containerd/containerd/pkg/encryption/keywrap/pkcs7"
+	"github.com/opencontainers/go-digest"
+	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
+	"github.com/pkg/errors"
+)
+
+func init() {
+	keyWrappers = make(map[string]keywrap.KeyWrapper)
+	keyWrapperAnnotations = make(map[string]string)
+	RegisterKeyWrapper("pgp", pgp.NewKeyWrapper())
+	RegisterKeyWrapper("jwe", jwe.NewKeyWrapper())
+	RegisterKeyWrapper("pkcs7", pkcs7.NewKeyWrapper())
+}
+
+var keyWrappers map[string]keywrap.KeyWrapper
+var keyWrapperAnnotations map[string]string
+
+// RegisterKeyWrapper allows to register key wrappers by their encryption scheme
+func RegisterKeyWrapper(scheme string, iface keywrap.KeyWrapper) {
+	keyWrappers[scheme] = iface
+	keyWrapperAnnotations[iface.GetAnnotationID()] = scheme
+}
+
+// GetKeyWrapper looks up the encryptor interface given an encryption scheme (gpg, jwe)
+func GetKeyWrapper(scheme string) keywrap.KeyWrapper {
+	return keyWrappers[scheme]
+}
+
+// GetWrappedKeysMap returns a map of wrappedKeys as values in a
+// map with the encryption scheme(s) as the key(s)
+func GetWrappedKeysMap(desc ocispec.Descriptor) map[string]string {
+	wrappedKeysMap := make(map[string]string)
+
+	for annotationsID, scheme := range keyWrapperAnnotations {
+		if annotation, ok := desc.Annotations[annotationsID]; ok {
+			wrappedKeysMap[scheme] = annotation
+		}
+	}
+	return wrappedKeysMap
+}
+
+// EncryptLayer encrypts the layer by running one encryptor after the other
+func EncryptLayer(ec *config.EncryptConfig, encOrPlainLayerReader io.Reader, desc ocispec.Descriptor) (io.Reader, map[string]string, error) {
+	var (
+		encLayerReader io.Reader
+		err            error
+		optsData       []byte
+	)
+
+	if ec == nil {
+		return nil, nil, errors.Wrapf(errdefs.ErrInvalidArgument, "EncryptConfig must not be nil")
+	}
+
+	for annotationsID := range keyWrapperAnnotations {
+		annotation := desc.Annotations[annotationsID]
+		if annotation != "" {
+			optsData, err = decryptLayerKeyOptsData(&ec.DecryptConfig, desc)
+			if err != nil {
+				return nil, nil, err
+			}
+			// already encrypted!
+		}
+	}
+
+	newAnnotations := make(map[string]string)
+
+	for annotationsID, scheme := range keyWrapperAnnotations {
+		b64Annotations := desc.Annotations[annotationsID]
+		if b64Annotations == "" && optsData == nil {
+			encLayerReader, optsData, err = commonEncryptLayer(encOrPlainLayerReader, desc.Digest, blockcipher.AESSIVCMAC512)
+			if err != nil {
+				return nil, nil, err
+			}
+		}
+		keywrapper := GetKeyWrapper(scheme)
+		b64Annotations, err = preWrapKeys(keywrapper, ec, b64Annotations, optsData)
+		if err != nil {
+			return nil, nil, err
+		}
+		if b64Annotations != "" {
+			newAnnotations[annotationsID] = b64Annotations
+		}
+	}
+	if len(newAnnotations) == 0 {
+		err = errors.Errorf("no encryptor found to handle encryption")
+	}
+	// if nothing was encrypted, we just return encLayer = nil
+	return encLayerReader, newAnnotations, err
+}
+
+// preWrapKeys calls WrapKeys and handles the base64 encoding and concatenation of the
+// annotation data
+func preWrapKeys(keywrapper keywrap.KeyWrapper, ec *config.EncryptConfig, b64Annotations string, optsData []byte) (string, error) {
+	newAnnotation, err := keywrapper.WrapKeys(ec, optsData)
+	if err != nil || len(newAnnotation) == 0 {
+		return b64Annotations, err
+	}
+	b64newAnnotation := base64.StdEncoding.EncodeToString(newAnnotation)
+	if b64Annotations == "" {
+		return b64newAnnotation, nil
+	}
+	return b64Annotations + "," + b64newAnnotation, nil
+}
+
+// DecryptLayer decrypts a layer trying one keywrap.KeyWrapper after the other to see whether it
+// can apply the provided private key
+// If unwrapOnly is set we will only try to decrypt the layer encryption key and return
+func DecryptLayer(dc *config.DecryptConfig, encLayerReader io.Reader, desc ocispec.Descriptor, unwrapOnly bool) (io.Reader, digest.Digest, error) {
+	if dc == nil {
+		return nil, "", errors.Wrapf(errdefs.ErrInvalidArgument, "DecryptConfig must not be nil")
+	}
+	optsData, err := decryptLayerKeyOptsData(dc, desc)
+	if err != nil || unwrapOnly {
+		return nil, "", err
+	}
+
+	return commonDecryptLayer(encLayerReader, optsData)
+}
+
+func decryptLayerKeyOptsData(dc *config.DecryptConfig, desc ocispec.Descriptor) ([]byte, error) {
+	privKeyGiven := false
+	for annotationsID, scheme := range keyWrapperAnnotations {
+		b64Annotation := desc.Annotations[annotationsID]
+		if b64Annotation != "" {
+			keywrapper := GetKeyWrapper(scheme)
+
+			if len(keywrapper.GetPrivateKeys(dc.Parameters)) == 0 {
+				continue
+			}
+			privKeyGiven = true
+
+			optsData, err := preUnwrapKey(keywrapper, dc, b64Annotation)
+			if err != nil {
+				// try next keywrap.KeyWrapper
+				continue
+			}
+			if optsData == nil {
+				// try next keywrap.KeyWrapper
+				continue
+			}
+			return optsData, nil
+		}
+	}
+	if !privKeyGiven {
+		return nil, errors.New("missing private key needed for decryption")
+	}
+	return nil, errors.Errorf("no suitable key unwrapper found or none of the private keys could be used for decryption")
+}
+
+// preUnwrapKey decodes the comma separated base64 strings and calls the Unwrap function
+// of the given keywrapper with it and returns the result in case the Unwrap functions
+// does not return an error. If all attempts fail, an error is returned.
+func preUnwrapKey(keywrapper keywrap.KeyWrapper, dc *config.DecryptConfig, b64Annotations string) ([]byte, error) {
+	if b64Annotations == "" {
+		return nil, nil
+	}
+	for _, b64Annotation := range strings.Split(b64Annotations, ",") {
+		annotation, err := base64.StdEncoding.DecodeString(b64Annotation)
+		if err != nil {
+			return nil, errors.New("could not base64 decode the annotation")
+		}
+		optsData, err := keywrapper.UnwrapKey(dc, annotation)
+		if err != nil {
+			continue
+		}
+		return optsData, nil
+	}
+	return nil, errors.New("no suitable key found for decrypting layer key")
+}
+
+// commonEncryptLayer is a function to encrypt the plain layer using a new random
+// symmetric key and return the LayerBlockCipherHandler's JSON in string form for
+// later use during decryption
+func commonEncryptLayer(plainLayerReader io.Reader, d digest.Digest, typ blockcipher.LayerCipherType) (io.Reader, []byte, error) {
+	lbch, err := blockcipher.NewLayerBlockCipherHandler()
+	if err != nil {
+		return nil, nil, err
+	}
+
+	encLayerReader, opts, err := lbch.Encrypt(plainLayerReader, typ)
+	if err != nil {
+		return nil, nil, err
+	}
+	opts.Digest = d
+
+	optsData, err := json.Marshal(opts)
+	if err != nil {
+		return nil, nil, errors.Wrapf(err, "could not JSON marshal opts")
+	}
+
+	return encLayerReader, optsData, err
+}
+
+// commonDecryptLayer decrypts an encrypted layer previously encrypted with commonEncryptLayer
+// by passing along the optsData
+func commonDecryptLayer(encLayerReader io.Reader, optsData []byte) (io.Reader, digest.Digest, error) {
+	opts := blockcipher.LayerBlockCipherOptions{}
+	err := json.Unmarshal(optsData, &opts)
+	if err != nil {
+		return nil, "", errors.Wrapf(err, "could not JSON unmarshal optsData")
+	}
+
+	lbch, err := blockcipher.NewLayerBlockCipherHandler()
+	if err != nil {
+		return nil, "", err
+	}
+
+	plainLayerReader, opts, err := lbch.Decrypt(encLayerReader, opts)
+	if err != nil {
+		return nil, "", err
+	}
+
+	return plainLayerReader, opts.Digest, nil
+}

pkg/encryption/encryption_test.go

@@ -21,7 +21,7 @@ import (
 	"reflect"
 	"testing"
 
-	"github.com/containerd/containerd/images/encryption/config"
+	"github.com/containerd/containerd/pkg/encryption/config"
 	digest "github.com/opencontainers/go-digest"
 	ocispec "github.com/opencontainers/image-spec/specs-go/v1"
 )

pkg/encryption/keywrap/jwe/keywrapper_jwe.go

@@ -19,9 +19,9 @@ package jwe
 import (
 	"crypto/ecdsa"
 
-	"github.com/containerd/containerd/images/encryption/config"
-	"github.com/containerd/containerd/images/encryption/keywrap"
-	"github.com/containerd/containerd/images/encryption/utils"
+	"github.com/containerd/containerd/pkg/encryption/config"
+	"github.com/containerd/containerd/pkg/encryption/keywrap"
+	"github.com/containerd/containerd/pkg/encryption/utils"
 	"github.com/pkg/errors"
 	jose "gopkg.in/square/go-jose.v2"
 )

pkg/encryption/keywrap/jwe/keywrapper_jwe_test.go

@@ -20,8 +20,8 @@ import (
 	"crypto/elliptic"
 	"testing"
 
-	"github.com/containerd/containerd/images/encryption/config"
-	"github.com/containerd/containerd/images/encryption/utils"
+	"github.com/containerd/containerd/pkg/encryption/config"
+	"github.com/containerd/containerd/pkg/encryption/utils"
 	jose "gopkg.in/square/go-jose.v2"
 )
 

pkg/encryption/keywrap/keywrap.go

@@ -17,7 +17,7 @@
 package keywrap
 
 import (
-	"github.com/containerd/containerd/images/encryption/config"
+	"github.com/containerd/containerd/pkg/encryption/config"
 )
 
 // KeyWrapper is the interface used for wrapping keys using

pkg/encryption/keywrap/pgp/keywrapper_gpg.go

@@ -29,8 +29,8 @@ import (
 	"strings"
 
 	"github.com/containerd/containerd/errdefs"
-	"github.com/containerd/containerd/images/encryption/config"
-	"github.com/containerd/containerd/images/encryption/keywrap"
+	"github.com/containerd/containerd/pkg/encryption/config"
+	"github.com/containerd/containerd/pkg/encryption/keywrap"
 	"github.com/pkg/errors"
 	"golang.org/x/crypto/openpgp"
 	"golang.org/x/crypto/openpgp/packet"

pkg/encryption/keywrap/pgp/keywrapper_gpg_test.go

@@ -19,7 +19,7 @@ package pgp
 import (
 	"testing"
 
-	"github.com/containerd/containerd/images/encryption/config"
+	"github.com/containerd/containerd/pkg/encryption/config"
 )
 
 var validGpgCcs = []*config.CryptoConfig{

pkg/encryption/keywrap/pkcs7/keywrapper_pkcs7.go

@@ -20,9 +20,9 @@ import (
 	"crypto"
 	"crypto/x509"
 
-	"github.com/containerd/containerd/images/encryption/config"
-	"github.com/containerd/containerd/images/encryption/keywrap"
-	"github.com/containerd/containerd/images/encryption/utils"
+	"github.com/containerd/containerd/pkg/encryption/config"
+	"github.com/containerd/containerd/pkg/encryption/keywrap"
+	"github.com/containerd/containerd/pkg/encryption/utils"
 	"github.com/fullsailor/pkcs7"
 	"github.com/pkg/errors"
 )

pkg/encryption/keywrap/pkcs7/keywrapper_pkcs7_test.go

@@ -20,8 +20,8 @@ import (
 	"crypto/x509"
 	"testing"
 
-	"github.com/containerd/containerd/images/encryption/config"
-	"github.com/containerd/containerd/images/encryption/utils"
+	"github.com/containerd/containerd/pkg/encryption/config"
+	"github.com/containerd/containerd/pkg/encryption/utils"
 )
 
 var oneEmpty []byte