Crypto library movement and changes to content helper interfaces
Signed-off-by: Derek McGowan <derek@mcgstyle.net>
This commit is contained in:
Derek McGowan
committed by
Brandon Lum
Brandon Lum
parent
bf8804c743
commit
dde436e65b
@@ -17,228 +17,461 @@
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package encryption
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import (
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"encoding/base64"
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"bytes"
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"context"
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"encoding/json"
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"fmt"
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"io"
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"strings"
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"math/rand"
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"github.com/containerd/containerd/images"
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"github.com/containerd/containerd/pkg/encryption"
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encconfig "github.com/containerd/containerd/pkg/encryption/config"
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"github.com/containerd/containerd/content"
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"github.com/containerd/containerd/errdefs"
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"github.com/containerd/containerd/images/encryption/blockcipher"
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"github.com/containerd/containerd/images/encryption/config"
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"github.com/containerd/containerd/images/encryption/keywrap"
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"github.com/containerd/containerd/images/encryption/keywrap/jwe"
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"github.com/containerd/containerd/images/encryption/keywrap/pgp"
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"github.com/containerd/containerd/images/encryption/keywrap/pkcs7"
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"github.com/opencontainers/go-digest"
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ocispec "github.com/opencontainers/image-spec/specs-go/v1"
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"github.com/containerd/containerd/leases"
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"github.com/containerd/containerd/platforms"
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digest "github.com/opencontainers/go-digest"
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specs "github.com/opencontainers/image-spec/specs-go"
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"github.com/pkg/errors"
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ocispec "github.com/opencontainers/image-spec/specs-go/v1"
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)
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func init() {
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keyWrappers = make(map[string]keywrap.KeyWrapper)
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keyWrapperAnnotations = make(map[string]string)
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RegisterKeyWrapper("pgp", pgp.NewKeyWrapper())
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RegisterKeyWrapper("jwe", jwe.NewKeyWrapper())
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RegisterKeyWrapper("pkcs7", pkcs7.NewKeyWrapper())
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type cryptoOp int
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const (
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cryptoOpEncrypt cryptoOp = iota
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cryptoOpDecrypt = iota
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cryptoOpUnwrapOnly = iota
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)
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// LayerFilter allows to select Layers by certain criteria
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type LayerFilter func(desc ocispec.Descriptor) bool
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// IsEncryptedDiff returns true if mediaType is a known encrypted media type.
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func IsEncryptedDiff(ctx context.Context, mediaType string) bool {
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switch mediaType {
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case images.MediaTypeDockerSchema2LayerGzipEnc, images.MediaTypeDockerSchema2LayerEnc:
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return true
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}
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return false
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}
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var keyWrappers map[string]keywrap.KeyWrapper
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var keyWrapperAnnotations map[string]string
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// RegisterKeyWrapper allows to register key wrappers by their encryption scheme
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func RegisterKeyWrapper(scheme string, iface keywrap.KeyWrapper) {
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keyWrappers[scheme] = iface
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keyWrapperAnnotations[iface.GetAnnotationID()] = scheme
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}
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// GetKeyWrapper looks up the encryptor interface given an encryption scheme (gpg, jwe)
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func GetKeyWrapper(scheme string) keywrap.KeyWrapper {
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return keyWrappers[scheme]
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}
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// GetWrappedKeysMap returns a map of wrappedKeys as values in a
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// map with the encryption scheme(s) as the key(s)
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func GetWrappedKeysMap(desc ocispec.Descriptor) map[string]string {
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wrappedKeysMap := make(map[string]string)
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for annotationsID, scheme := range keyWrapperAnnotations {
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if annotation, ok := desc.Annotations[annotationsID]; ok {
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wrappedKeysMap[scheme] = annotation
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// HasEncryptedLayer returns true if any LayerInfo indicates that the layer is encrypted
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func HasEncryptedLayer(ctx context.Context, layerInfos []ocispec.Descriptor) bool {
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for i := 0; i < len(layerInfos); i++ {
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if IsEncryptedDiff(ctx, layerInfos[i].MediaType) {
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return true
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}
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}
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return wrappedKeysMap
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return false
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}
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// EncryptLayer encrypts the layer by running one encryptor after the other
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func EncryptLayer(ec *config.EncryptConfig, encOrPlainLayerReader io.Reader, desc ocispec.Descriptor) (io.Reader, map[string]string, error) {
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// encryptLayer encrypts the layer using the CryptoConfig and creates a new OCI Descriptor.
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// A call to this function may also only manipulate the wrapped keys list.
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// The caller is expected to store the returned encrypted data and OCI Descriptor
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func encryptLayer(cc *encconfig.CryptoConfig, dataReader content.ReaderAt, desc ocispec.Descriptor) (ocispec.Descriptor, io.Reader, error) {
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var (
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encLayerReader io.Reader
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err error
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optsData []byte
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size int64
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d digest.Digest
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err error
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)
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if ec == nil {
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return nil, nil, errors.Wrapf(errdefs.ErrInvalidArgument, "EncryptConfig must not be nil")
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encLayerReader, annotations, err := encryption.EncryptLayer(cc.EncryptConfig, encryption.ReaderFromReaderAt(dataReader), desc)
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if err != nil {
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return ocispec.Descriptor{}, nil, err
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}
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for annotationsID := range keyWrapperAnnotations {
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annotation := desc.Annotations[annotationsID]
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if annotation != "" {
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optsData, err = decryptLayerKeyOptsData(&ec.DecryptConfig, desc)
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if err != nil {
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return nil, nil, err
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}
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// already encrypted!
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}
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// were data touched ?
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if encLayerReader != nil {
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size = 0
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d = ""
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} else {
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size = desc.Size
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d = desc.Digest
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}
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newAnnotations := make(map[string]string)
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newDesc := ocispec.Descriptor{
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Digest: d,
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Size: size,
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Platform: desc.Platform,
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Annotations: annotations,
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}
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for annotationsID, scheme := range keyWrapperAnnotations {
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b64Annotations := desc.Annotations[annotationsID]
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if b64Annotations == "" && optsData == nil {
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encLayerReader, optsData, err = commonEncryptLayer(encOrPlainLayerReader, desc.Digest, blockcipher.AESSIVCMAC512)
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if err != nil {
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return nil, nil, err
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}
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}
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keywrapper := GetKeyWrapper(scheme)
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b64Annotations, err = preWrapKeys(keywrapper, ec, b64Annotations, optsData)
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if err != nil {
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return nil, nil, err
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}
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if b64Annotations != "" {
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newAnnotations[annotationsID] = b64Annotations
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}
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switch desc.MediaType {
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case images.MediaTypeDockerSchema2LayerGzip:
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newDesc.MediaType = images.MediaTypeDockerSchema2LayerGzipEnc
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case images.MediaTypeDockerSchema2Layer:
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newDesc.MediaType = images.MediaTypeDockerSchema2LayerEnc
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case images.MediaTypeDockerSchema2LayerGzipEnc:
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newDesc.MediaType = images.MediaTypeDockerSchema2LayerGzipEnc
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case images.MediaTypeDockerSchema2LayerEnc:
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newDesc.MediaType = images.MediaTypeDockerSchema2LayerEnc
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// TODO: Mediatypes to be added in ocispec
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case ocispec.MediaTypeImageLayerGzip:
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newDesc.MediaType = images.MediaTypeDockerSchema2LayerGzipEnc
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case ocispec.MediaTypeImageLayer:
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newDesc.MediaType = images.MediaTypeDockerSchema2LayerEnc
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default:
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return ocispec.Descriptor{}, nil, errors.Errorf("Encryption: unsupporter layer MediaType: %s\n", desc.MediaType)
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}
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if len(newAnnotations) == 0 {
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err = errors.Errorf("no encryptor found to handle encryption")
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}
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// if nothing was encrypted, we just return encLayer = nil
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return encLayerReader, newAnnotations, err
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return newDesc, encLayerReader, nil
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}
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// preWrapKeys calls WrapKeys and handles the base64 encoding and concatenation of the
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// annotation data
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func preWrapKeys(keywrapper keywrap.KeyWrapper, ec *config.EncryptConfig, b64Annotations string, optsData []byte) (string, error) {
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newAnnotation, err := keywrapper.WrapKeys(ec, optsData)
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if err != nil || len(newAnnotation) == 0 {
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return b64Annotations, err
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}
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b64newAnnotation := base64.StdEncoding.EncodeToString(newAnnotation)
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if b64Annotations == "" {
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return b64newAnnotation, nil
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}
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return b64Annotations + "," + b64newAnnotation, nil
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}
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// DecryptLayer decrypts a layer trying one keywrap.KeyWrapper after the other to see whether it
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// can apply the provided private key
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// If unwrapOnly is set we will only try to decrypt the layer encryption key and return
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func DecryptLayer(dc *config.DecryptConfig, encLayerReader io.Reader, desc ocispec.Descriptor, unwrapOnly bool) (io.Reader, digest.Digest, error) {
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if dc == nil {
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return nil, "", errors.Wrapf(errdefs.ErrInvalidArgument, "DecryptConfig must not be nil")
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}
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optsData, err := decryptLayerKeyOptsData(dc, desc)
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// decryptLayer decrypts the layer using the CryptoConfig and creates a new OCI Descriptor.
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// The caller is expected to store the returned plain data and OCI Descriptor
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func decryptLayer(cc *encconfig.CryptoConfig, dataReader content.ReaderAt, desc ocispec.Descriptor, unwrapOnly bool) (ocispec.Descriptor, io.Reader, error) {
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resultReader, d, err := encryption.DecryptLayer(cc.DecryptConfig, encryption.ReaderFromReaderAt(dataReader), desc, unwrapOnly)
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if err != nil || unwrapOnly {
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return nil, "", err
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return ocispec.Descriptor{}, nil, err
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}
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return commonDecryptLayer(encLayerReader, optsData)
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newDesc := ocispec.Descriptor{
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Digest: d,
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Size: 0,
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Platform: desc.Platform,
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}
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switch desc.MediaType {
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case images.MediaTypeDockerSchema2LayerGzipEnc:
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newDesc.MediaType = images.MediaTypeDockerSchema2LayerGzip
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case images.MediaTypeDockerSchema2LayerEnc:
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newDesc.MediaType = images.MediaTypeDockerSchema2Layer
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default:
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return ocispec.Descriptor{}, nil, errors.Errorf("Decryption: unsupporter layer MediaType: %s\n", desc.MediaType)
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}
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return newDesc, resultReader, nil
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}
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func decryptLayerKeyOptsData(dc *config.DecryptConfig, desc ocispec.Descriptor) ([]byte, error) {
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privKeyGiven := false
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for annotationsID, scheme := range keyWrapperAnnotations {
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b64Annotation := desc.Annotations[annotationsID]
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if b64Annotation != "" {
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keywrapper := GetKeyWrapper(scheme)
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// cryptLayer handles the changes due to encryption or decryption of a layer
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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) {
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var (
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resultReader io.Reader
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newDesc ocispec.Descriptor
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)
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if len(keywrapper.GetPrivateKeys(dc.Parameters)) == 0 {
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continue
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dataReader, err := cs.ReaderAt(ctx, desc)
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if err != nil {
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return ocispec.Descriptor{}, err
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}
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defer dataReader.Close()
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if cryptoOp == cryptoOpEncrypt {
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newDesc, resultReader, err = encryptLayer(cc, dataReader, desc)
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} else {
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newDesc, resultReader, err = decryptLayer(cc, dataReader, desc, cryptoOp == cryptoOpUnwrapOnly)
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}
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if err != nil || cryptoOp == cryptoOpUnwrapOnly {
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return ocispec.Descriptor{}, err
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}
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// some operations, such as changing recipients, may not touch the layer at all
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if resultReader != nil {
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if ls == nil {
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return ocispec.Descriptor{}, errors.New("Unexpected write to object without lease")
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}
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var rsrc leases.Resource
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var ref string
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// If we have the digest, write blob with checks
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haveDigest := newDesc.Digest.String() != ""
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if haveDigest {
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ref = fmt.Sprintf("layer-%s", newDesc.Digest.String())
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rsrc = leases.Resource{
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ID: newDesc.Digest.String(),
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Type: "content",
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}
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} else {
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ref = fmt.Sprintf("blob-%d-%d", rand.Int(), rand.Int())
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rsrc = leases.Resource{
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ID: ref,
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Type: "ingests",
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}
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privKeyGiven = true
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optsData, err := preUnwrapKey(keywrapper, dc, b64Annotation)
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}
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// Add resource to lease and write blob
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if err := ls.AddResource(ctx, l, rsrc); err != nil {
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return ocispec.Descriptor{}, errors.Wrap(err, "Unable to add resource to lease")
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}
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if haveDigest {
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if err := content.WriteBlob(ctx, cs, ref, resultReader, newDesc); err != nil {
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return ocispec.Descriptor{}, errors.Wrap(err, "failed to write config")
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}
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} else {
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newDesc.Digest, newDesc.Size, err = ingestReader(ctx, cs, ref, resultReader)
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if err != nil {
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// try next keywrap.KeyWrapper
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continue
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return ocispec.Descriptor{}, err
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}
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if optsData == nil {
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// try next keywrap.KeyWrapper
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continue
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}
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}
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return newDesc, err
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}
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func ingestReader(ctx context.Context, cs content.Ingester, ref string, r io.Reader) (digest.Digest, int64, error) {
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cw, err := content.OpenWriter(ctx, cs, content.WithRef(ref))
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if err != nil {
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return "", 0, errors.Wrap(err, "failed to open writer")
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}
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defer cw.Close()
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if _, err := content.CopyReader(cw, r); err != nil {
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return "", 0, errors.Wrap(err, "copy failed")
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}
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st, err := cw.Status()
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if err != nil {
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return "", 0, errors.Wrap(err, "failed to get state")
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}
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if err := cw.Commit(ctx, st.Offset, ""); err != nil {
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if !errdefs.IsAlreadyExists(err) {
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return "", 0, errors.Wrapf(err, "failed commit on ref %q", ref)
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}
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}
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return cw.Digest(), st.Offset, nil
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}
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// Encrypt or decrypt all the Children of a given descriptor
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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) {
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children, err := images.Children(ctx, cs, desc)
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if err != nil {
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if errdefs.IsNotFound(err) {
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return desc, false, nil
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}
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return ocispec.Descriptor{}, false, err
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}
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var newLayers []ocispec.Descriptor
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var config ocispec.Descriptor
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modified := false
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for _, child := range children {
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// we only encrypt child layers and have to update their parents if encryption happened
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switch child.MediaType {
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case images.MediaTypeDockerSchema2Config, ocispec.MediaTypeImageConfig:
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config = child
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case images.MediaTypeDockerSchema2LayerGzip, images.MediaTypeDockerSchema2Layer,
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ocispec.MediaTypeImageLayerGzip, ocispec.MediaTypeImageLayer:
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if cryptoOp == cryptoOpEncrypt && lf(child) {
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nl, err := cryptLayer(ctx, cs, ls, l, child, cc, cryptoOp)
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if err != nil {
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return ocispec.Descriptor{}, false, err
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}
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modified = true
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newLayers = append(newLayers, nl)
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} else {
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newLayers = append(newLayers, child)
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}
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return optsData, nil
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case images.MediaTypeDockerSchema2LayerGzipEnc, images.MediaTypeDockerSchema2LayerEnc:
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// this one can be decrypted but also its recipients list changed
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if lf(child) {
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nl, err := cryptLayer(ctx, cs, ls, l, child, cc, cryptoOp)
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if err != nil || cryptoOp == cryptoOpUnwrapOnly {
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return ocispec.Descriptor{}, false, err
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}
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modified = true
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newLayers = append(newLayers, nl)
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} else {
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newLayers = append(newLayers, child)
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}
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case images.MediaTypeDockerSchema2LayerForeign, images.MediaTypeDockerSchema2LayerForeignGzip:
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// never encrypt/decrypt
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newLayers = append(newLayers, child)
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default:
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return ocispec.Descriptor{}, false, errors.Errorf("bad/unhandled MediaType %s in encryptChildren\n", child.MediaType)
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}
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}
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if !privKeyGiven {
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return nil, errors.New("missing private key needed for decryption")
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}
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return nil, errors.Errorf("no suitable key unwrapper found or none of the private keys could be used for decryption")
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}
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// preUnwrapKey decodes the comma separated base64 strings and calls the Unwrap function
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// of the given keywrapper with it and returns the result in case the Unwrap functions
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// does not return an error. If all attempts fail, an error is returned.
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func preUnwrapKey(keywrapper keywrap.KeyWrapper, dc *config.DecryptConfig, b64Annotations string) ([]byte, error) {
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if b64Annotations == "" {
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return nil, nil
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}
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for _, b64Annotation := range strings.Split(b64Annotations, ",") {
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annotation, err := base64.StdEncoding.DecodeString(b64Annotation)
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if modified && len(newLayers) > 0 {
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newManifest := ocispec.Manifest{
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Versioned: specs.Versioned{
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SchemaVersion: 2,
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},
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Config: config,
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Layers: newLayers,
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}
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mb, err := json.MarshalIndent(newManifest, "", " ")
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if err != nil {
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return nil, errors.New("could not base64 decode the annotation")
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return ocispec.Descriptor{}, false, errors.Wrap(err, "failed to marshal image")
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}
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optsData, err := keywrapper.UnwrapKey(dc, annotation)
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newDesc := ocispec.Descriptor{
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MediaType: ocispec.MediaTypeImageManifest,
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Size: int64(len(mb)),
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Digest: digest.Canonical.FromBytes(mb),
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Platform: desc.Platform,
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}
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labels := map[string]string{}
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labels["containerd.io/gc.ref.content.0"] = newManifest.Config.Digest.String()
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for i, ch := range newManifest.Layers {
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labels[fmt.Sprintf("containerd.io/gc.ref.content.%d", i+1)] = ch.Digest.String()
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}
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ref := fmt.Sprintf("manifest-%s", newDesc.Digest.String())
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if ls == nil {
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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
|
||||
}
|
||||
|
||||
Reference in New Issue
Block a user