working commit

vendor/helm.sh/helm/v4/internal/plugin/sign.go

@@ -0,0 +1,156 @@
+/*
+Copyright The Helm 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 plugin
+
+import (
+	"archive/tar"
+	"bytes"
+	"compress/gzip"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+
+	"sigs.k8s.io/yaml"
+
+	"helm.sh/helm/v4/pkg/provenance"
+)
+
+// SignPlugin signs a plugin using the SHA256 hash of the tarball data.
+//
+// This is used when packaging and signing a plugin from tarball data.
+// It creates a signature that includes the tarball hash and plugin metadata,
+// allowing verification of the original tarball later.
+func SignPlugin(tarballData []byte, filename string, signer *provenance.Signatory) (string, error) {
+	// Extract plugin metadata from tarball data
+	pluginMeta, err := ExtractTgzPluginMetadata(bytes.NewReader(tarballData))
+	if err != nil {
+		return "", fmt.Errorf("failed to extract plugin metadata: %w", err)
+	}
+
+	// Marshal plugin metadata to YAML bytes
+	metadataBytes, err := yaml.Marshal(pluginMeta)
+	if err != nil {
+		return "", fmt.Errorf("failed to marshal plugin metadata: %w", err)
+	}
+
+	// Use the generic provenance signing function
+	return signer.ClearSign(tarballData, filename, metadataBytes)
+}
+
+// ExtractTgzPluginMetadata extracts plugin metadata from a gzipped tarball reader
+func ExtractTgzPluginMetadata(r io.Reader) (*Metadata, error) {
+	gzr, err := gzip.NewReader(r)
+	if err != nil {
+		return nil, err
+	}
+	defer gzr.Close()
+
+	tr := tar.NewReader(gzr)
+	for {
+		header, err := tr.Next()
+		if errors.Is(err, io.EOF) {
+			break
+		}
+		if err != nil {
+			return nil, err
+		}
+
+		// Look for plugin.yaml file
+		if filepath.Base(header.Name) == "plugin.yaml" {
+			data, err := io.ReadAll(tr)
+			if err != nil {
+				return nil, err
+			}
+
+			// Parse the plugin metadata
+			metadata, err := loadMetadata(data)
+			if err != nil {
+				return nil, err
+			}
+
+			return metadata, nil
+		}
+	}
+
+	return nil, errors.New("plugin.yaml not found in tarball")
+}
+
+// parsePluginMessageBlock parses a signed message block to extract plugin metadata and checksums
+func parsePluginMessageBlock(data []byte) (*Metadata, *provenance.SumCollection, error) {
+	sc := &provenance.SumCollection{}
+
+	// We only need the checksums for verification, not the full metadata
+	if err := provenance.ParseMessageBlock(data, nil, sc); err != nil {
+		return nil, sc, err
+	}
+	return nil, sc, nil
+}
+
+// CreatePluginTarball creates a gzipped tarball from a plugin directory
+func CreatePluginTarball(sourceDir, pluginName string, w io.Writer) error {
+	gzw := gzip.NewWriter(w)
+	defer gzw.Close()
+
+	tw := tar.NewWriter(gzw)
+	defer tw.Close()
+
+	// Use the plugin name as the base directory in the tarball
+	baseDir := pluginName
+
+	// Walk the directory tree
+	return filepath.Walk(sourceDir, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		// Create header
+		header, err := tar.FileInfoHeader(info, "")
+		if err != nil {
+			return err
+		}
+
+		// Update the name to be relative to the source directory
+		relPath, err := filepath.Rel(sourceDir, path)
+		if err != nil {
+			return err
+		}
+
+		// Include the base directory name in the tarball
+		header.Name = filepath.Join(baseDir, relPath)
+
+		// Write header
+		if err := tw.WriteHeader(header); err != nil {
+			return err
+		}
+
+		// If it's a regular file, write its content
+		if info.Mode().IsRegular() {
+			file, err := os.Open(path)
+			if err != nil {
+				return err
+			}
+			defer file.Close()
+
+			if _, err := io.Copy(tw, file); err != nil {
+				return err
+			}
+		}
+
+		return nil
+	})
+}