Add public bundle manifest package

pkg/bundle/validate.go

@@ -0,0 +1,79 @@
+package bundle
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+)
+
+func ValidateManifest(manifest Manifest) error {
+	if manifest.SchemaVersion != SchemaVersion {
+		return fmt.Errorf("schema_version must be %d", SchemaVersion)
+	}
+	if manifest.ID == "" {
+		return fmt.Errorf("id is required")
+	}
+	if err := validateDigest(manifest.Digest); err != nil {
+		return fmt.Errorf("digest: %w", err)
+	}
+	if manifest.Created.IsZero() {
+		return fmt.Errorf("created is required")
+	}
+	if len(manifest.Files) == 0 {
+		return fmt.Errorf("files is required")
+	}
+	seen := make(map[string]struct{}, len(manifest.Files))
+	for index, file := range manifest.Files {
+		if err := ValidateSourcePath(file.Path); err != nil {
+			return fmt.Errorf("files[%d].path: %w", index, err)
+		}
+		if err := validateDigest(file.SHA256); err != nil {
+			return fmt.Errorf("files[%d].sha256: %w", index, err)
+		}
+		if file.Size < 0 {
+			return fmt.Errorf("files[%d].size must be non-negative", index)
+		}
+		if _, exists := seen[file.Path]; exists {
+			return fmt.Errorf("files[%d].path duplicates %q", index, file.Path)
+		}
+		seen[file.Path] = struct{}{}
+	}
+	if actual := BundleDigest(manifest.Files); actual != manifest.Digest {
+		return fmt.Errorf("digest mismatch: got %s want %s", actual, manifest.Digest)
+	}
+	return nil
+}
+
+func ValidateBundle(root string, manifest Manifest) error {
+	if err := ValidateManifest(manifest); err != nil {
+		return err
+	}
+	files := append([]ManifestFile(nil), manifest.Files...)
+	for index, manifestFile := range files {
+		fullPath := filepath.Join(root, filepath.FromSlash(manifestFile.Path))
+		info, err := os.Lstat(fullPath)
+		if err != nil {
+			return fmt.Errorf("file %q stat: %w", manifestFile.Path, err)
+		}
+		if !info.Mode().IsRegular() {
+			return fmt.Errorf("file %q must be a regular file", manifestFile.Path)
+		}
+		if info.Size() != manifestFile.Size {
+			return fmt.Errorf("file %q size mismatch: got %d want %d", manifestFile.Path, info.Size(), manifestFile.Size)
+		}
+		data, err := os.ReadFile(fullPath)
+		if err != nil {
+			return fmt.Errorf("file %q read: %w", manifestFile.Path, err)
+		}
+		actualDigest := FileDigest(data)
+		if actualDigest != manifestFile.SHA256 {
+			return fmt.Errorf("file %q sha256 mismatch: got %s want %s", manifestFile.Path, actualDigest, manifestFile.SHA256)
+		}
+		files[index].SHA256 = actualDigest
+		files[index].Size = int64(len(data))
+	}
+	if actualDigest := BundleDigest(files); actualDigest != manifest.Digest {
+		return fmt.Errorf("digest mismatch: got %s want %s", actualDigest, manifest.Digest)
+	}
+	return nil
+}