Reject unsupported encryption/decryption updates in UpdateLayerInfos

Signed-off-by: Miloslav Trmač <mitr@redhat.com>
containers · May 4, 2023 · 2699a9e · 2699a9e
1 parent b3f44a7
commit 2699a9e
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Showing 4 changed files with 154 additions and 0 deletions.
diff --git a/manifest/docker_schema1.go b/manifest/docker_schema1.go
@@ -154,6 +154,9 @@ func (m *Schema1) UpdateLayerInfos(layerInfos []types.BlobInfo) error {
 		// but (docker pull) ignores them in favor of computing DiffIDs from uncompressed data, except verifying the child->parent links and uniqueness.
 		// So, we don't bother recomputing the IDs in m.History.V1Compatibility.
 		m.FSLayers[(len(layerInfos)-1)-i].BlobSum = info.Digest
+		if info.CryptoOperation != types.PreserveOriginalCrypto {
+			return fmt.Errorf("encryption change (for layer %q) is not supported in schema2 manifests", info.Digest)
+		}
 	}
 	return nil
 }

diff --git a/manifest/docker_schema1_test.go b/manifest/docker_schema1_test.go
@@ -6,6 +6,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/containers/image/v5/pkg/compression"
 	"github.com/containers/image/v5/types"
 	"github.com/opencontainers/go-digest"
 	"github.com/stretchr/testify/assert"
@@ -177,6 +178,91 @@ func TestSchema1LayerInfos(t *testing.T) {
 	}, m.LayerInfos())
 }
 
+func TestSchema1UpdateLayerInfos(t *testing.T) {
+	for _, c := range []struct {
+		name            string
+		sourceFixture   string
+		updates         []types.BlobInfo
+		expectedFixture string // or "" to indicate an expected failure
+	}{
+		// Many more tests cases could be added here
+		{
+			name:          "uncompressed → gzip encrypted",
+			sourceFixture: "v2s1.manifest.json",
+			updates: []types.BlobInfo{
+				{
+					Digest:               "sha256:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
+					Size:                 32654,
+					Annotations:          map[string]string{"org.opencontainers.image.enc.…": "layer1"},
+					CompressionOperation: types.Compress,
+					CompressionAlgorithm: &compression.Gzip,
+					CryptoOperation:      types.Encrypt,
+				},
+				{
+					Digest:               "sha256:bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb",
+					Size:                 16724,
+					Annotations:          map[string]string{"org.opencontainers.image.enc.…": "layer2"},
+					CompressionOperation: types.Compress,
+					CompressionAlgorithm: &compression.Gzip,
+					CryptoOperation:      types.Encrypt,
+				},
+				{
+					Digest:               "sha256:cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc",
+					Size:                 73109,
+					Annotations:          map[string]string{"org.opencontainers.image.enc.…": "layer2"},
+					CompressionOperation: types.Compress,
+					CompressionAlgorithm: &compression.Gzip,
+					CryptoOperation:      types.Encrypt,
+				},
+			},
+			expectedFixture: "", // Encryption is not supported
+		},
+		{
+			name:          "gzip  → uncompressed decrypted", // We can’t represent encrypted images anyway, but verify that we reject decryption attempts.
+			sourceFixture: "v2s1.manifest.json",
+			updates: []types.BlobInfo{
+				{
+					Digest:               "sha256:e692418e4cbaf90ca69d05a66403747baa33ee08806650b51fab815ad7fc331f",
+					Size:                 32654,
+					CompressionOperation: types.Decompress,
+					CryptoOperation:      types.Decrypt,
+				},
+				{
+					Digest:               "sha256:3c3a4604a545cdc127456d94e421cd355bca5b528f4a9c1905b15da2eb4a4c6b",
+					Size:                 16724,
+					CompressionOperation: types.Decompress,
+					CryptoOperation:      types.Decrypt,
+				},
+				{
+					Digest:               "sha256:ec4b8955958665577945c89419d1af06b5f7636b4ac3da7f12184802ad867736",
+					Size:                 73109,
+					CompressionOperation: types.Decompress,
+					CryptoOperation:      types.Decrypt,
+				},
+			},
+			expectedFixture: "", // Decryption is not supported
+		},
+	} {
+		manifest := manifestSchema1FromFixture(t, c.sourceFixture)
+
+		err := manifest.UpdateLayerInfos(c.updates)
+		if c.expectedFixture == "" {
+			assert.Error(t, err, c.name)
+		} else {
+			require.NoError(t, err, c.name)
+
+			updatedManifestBytes, err := manifest.Serialize()
+			require.NoError(t, err, c.name)
+
+			expectedManifest := manifestSchema1FromFixture(t, c.expectedFixture)
+			expectedManifestBytes, err := expectedManifest.Serialize()
+			require.NoError(t, err, c.name)
+
+			assert.Equal(t, string(expectedManifestBytes), string(updatedManifestBytes), c.name)
+		}
+	}
+}
+
 func TestSchema1ImageID(t *testing.T) {
 	m := manifestSchema1FromFixture(t, "schema2-to-schema1-by-docker.json")
 	id, err := m.ImageID(schema1FixtureLayerDiffIDs)

diff --git a/manifest/docker_schema2.go b/manifest/docker_schema2.go
@@ -247,6 +247,9 @@ func (m *Schema2) UpdateLayerInfos(layerInfos []types.BlobInfo) error {
 		m.LayersDescriptors[i].Digest = info.Digest
 		m.LayersDescriptors[i].Size = info.Size
 		m.LayersDescriptors[i].URLs = info.URLs
+		if info.CryptoOperation != types.PreserveOriginalCrypto {
+			return fmt.Errorf("encryption change (for layer %q) is not supported in schema2 manifests", info.Digest)
+		}
 	}
 	return nil
 }

diff --git a/manifest/docker_schema2_test.go b/manifest/docker_schema2_test.go
@@ -179,6 +179,68 @@ func TestSchema2UpdateLayerInfos(t *testing.T) {
 			},
 			expectedFixture: "v2s2.nondistributable.manifest.json",
 		},
+		{
+			name:          "uncompressed → gzip encrypted",
+			sourceFixture: "v2s2.uncompressed.manifest.json",
+			updates: []types.BlobInfo{
+				{
+					Digest:               "sha256:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
+					Size:                 32654,
+					Annotations:          map[string]string{"org.opencontainers.image.enc.…": "layer1"},
+					MediaType:            DockerV2SchemaLayerMediaTypeUncompressed,
+					CompressionOperation: types.Compress,
+					CompressionAlgorithm: &compression.Gzip,
+					CryptoOperation:      types.Encrypt,
+				},
+				{
+					Digest:               "sha256:bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb",
+					Size:                 16724,
+					Annotations:          map[string]string{"org.opencontainers.image.enc.…": "layer2"},
+					MediaType:            DockerV2SchemaLayerMediaTypeUncompressed,
+					CompressionOperation: types.Compress,
+					CompressionAlgorithm: &compression.Gzip,
+					CryptoOperation:      types.Encrypt,
+				},
+				{
+					Digest:               "sha256:cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc",
+					Size:                 73109,
+					Annotations:          map[string]string{"org.opencontainers.image.enc.…": "layer2"},
+					MediaType:            DockerV2SchemaLayerMediaTypeUncompressed,
+					CompressionOperation: types.Compress,
+					CompressionAlgorithm: &compression.Gzip,
+					CryptoOperation:      types.Encrypt,
+				},
+			},
+			expectedFixture: "", // Encryption is not supported
+		},
+		{
+			name:          "gzip  → uncompressed decrypted", // We can’t represent encrypted images anyway, but verify that we reject decryption attempts.
+			sourceFixture: "v2s2.manifest.json",
+			updates: []types.BlobInfo{
+				{
+					Digest:               "sha256:e692418e4cbaf90ca69d05a66403747baa33ee08806650b51fab815ad7fc331f",
+					Size:                 32654,
+					MediaType:            DockerV2Schema2LayerMediaType,
+					CompressionOperation: types.Decompress,
+					CryptoOperation:      types.Decrypt,
+				},
+				{
+					Digest:               "sha256:3c3a4604a545cdc127456d94e421cd355bca5b528f4a9c1905b15da2eb4a4c6b",
+					Size:                 16724,
+					MediaType:            DockerV2Schema2LayerMediaType,
+					CompressionOperation: types.Decompress,
+					CryptoOperation:      types.Decrypt,
+				},
+				{
+					Digest:               "sha256:ec4b8955958665577945c89419d1af06b5f7636b4ac3da7f12184802ad867736",
+					Size:                 73109,
+					MediaType:            DockerV2Schema2LayerMediaType,
+					CompressionOperation: types.Decompress,
+					CryptoOperation:      types.Decrypt,
+				},
+			},
+			expectedFixture: "", // Decryption is not supported
+		},
 	} {
 		manifest := manifestSchema2FromFixture(t, c.sourceFixture)