feat: crl cache (#462)

Signed-off-by: Patrick Zheng <[email protected]>

dir/fs.go

@@ -58,3 +58,10 @@ func ConfigFS() SysFS {
 func PluginFS() SysFS {
 	return NewSysFS(filepath.Join(userLibexecDirPath(), PathPlugins))
 }
+
+// CacheFS is the cache SysFS.
+//
+// To get the root of crl file cache, use `CacheFS().SysFS(PathCRLCache)`.
+func CacheFS() SysFS {
+	return NewSysFS(userCacheDirPath())
+}

dir/fs_test.go

@@ -71,3 +71,14 @@ func TestPluginFS(t *testing.T) {
 		t.Fatalf(`SysPath() failed. got: %q, want: %q`, path, filepath.Join(userLibexecDirPath(), PathPlugins, "plugin"))
 	}
 }
+
+func TestCRLFileCacheFS(t *testing.T) {
+	cacheFS := CacheFS()
+	path, err := cacheFS.SysPath(PathCRLCache)
+	if err != nil {
+		t.Fatalf("SysPath() failed. err = %v", err)
+	}
+	if path != filepath.Join(UserCacheDir, PathCRLCache) {
+		t.Fatalf(`SysPath() failed. got: %q, want: %q`, path, UserConfigDir)
+	}
+}

dir/path.go

@@ -12,7 +12,7 @@
 // limitations under the License.
 
 // Package dir implements Notation directory structure.
-// [directory spec]: https://github.com/notaryproject/notation/blob/main/specs/directory.md
+// [directory spec]: https://notaryproject.dev/docs/user-guides/how-to/directory-structure/
 //
 // Example:
 //
@@ -31,7 +31,7 @@
 //   - Set custom configurations directory:
 //     dir.UserConfigDir = '/path/to/configurations/'
 //
-// Only user level directory is supported for RC.1, and system level directory
+// Only user level directory is supported, and system level directory
 // may be added later.
 package dir
 
@@ -44,6 +44,7 @@ import (
 var (
 	UserConfigDir  string // Absolute path of user level {NOTATION_CONFIG}
 	UserLibexecDir string // Absolute path of user level {NOTATION_LIBEXEC}
+	UserCacheDir   string // Absolute path of user level {NOTATION_CACHE}
 )
 
 const (
@@ -65,8 +66,6 @@ const (
 	PathOCITrustPolicy = "trustpolicy.oci.json"
 	// PathBlobTrustPolicy is the Blob trust policy file relative path.
 	PathBlobTrustPolicy = "trustpolicy.blob.json"
-	// PathPlugins is the plugins directory relative path.
-	PathPlugins = "plugins"
 	// LocalKeysDir is the directory name for local key relative path.
 	LocalKeysDir = "localkeys"
 	// LocalCertificateExtension defines the extension of the certificate files.
@@ -77,7 +76,24 @@ const (
 	TrustStoreDir = "truststore"
 )
 
-var userConfigDir = os.UserConfigDir // for unit test
+// The relative path to {NOTATION_LIBEXEC}
+const (
+	// PathPlugins is the plugins directory relative path.
+	PathPlugins = "plugins"
+)
+
+// The relative path to {NOTATION_CACHE}
+const (
+	// PathCRLCache is the crl file cache directory relative path.
+	PathCRLCache = "crl"
+)
+
+// for unit tests
+var (
+	userConfigDir = os.UserConfigDir
+
+	userCacheDir = os.UserCacheDir
+)
 
 // userConfigDirPath returns the user level {NOTATION_CONFIG} path.
 func userConfigDirPath() string {
@@ -103,6 +119,21 @@ func userLibexecDirPath() string {
 	return UserLibexecDir
 }
 
+// userCacheDirPath returns the user level {NOTATION_CACHE} path.
+func userCacheDirPath() string {
+	if UserCacheDir == "" {
+		userDir, err := userCacheDir()
+		if err != nil {
+			// fallback to current directory
+			UserCacheDir = filepath.Join("."+notation, "cache")
+			return UserCacheDir
+		}
+		// set user cache
+		UserCacheDir = filepath.Join(userDir, notation)
+	}
+	return UserCacheDir
+}
+
 // LocalKeyPath returns the local key and local cert relative paths.
 func LocalKeyPath(name string) (keyPath, certPath string) {
 	basePath := path.Join(LocalKeysDir, name)

dir/path_test.go

@@ -15,20 +15,22 @@ package dir
 
 import (
 	"os"
+	"path/filepath"
 	"testing"
 )
 
-func mockGetUserConfig() (string, error) {
+func mockUserPath() (string, error) {
 	return "/path/", nil
 }
 
 func setup() {
 	UserConfigDir = ""
 	UserLibexecDir = ""
+	UserCacheDir = ""
 }
 
 func Test_UserConfigDirPath(t *testing.T) {
-	userConfigDir = mockGetUserConfig
+	userConfigDir = mockUserPath
 	setup()
 	got := userConfigDirPath()
 	if got != "/path/notation" {
@@ -39,25 +41,40 @@ func Test_UserConfigDirPath(t *testing.T) {
 func Test_NoHomeVariable(t *testing.T) {
 	t.Setenv("HOME", "")
 	t.Setenv("XDG_CONFIG_HOME", "")
+	t.Setenv("XDG_CACHE_HOME", "")
 	setup()
 	userConfigDir = os.UserConfigDir
 	got := userConfigDirPath()
 	if got != ".notation" {
-		t.Fatalf(`UserConfigDirPath() = %q, want ".notation"`, UserConfigDir)
+		t.Fatalf(`userConfigDirPath() = %q, want ".notation"`, got)
+	}
+	got = userCacheDirPath()
+	want := filepath.Join("."+notation, "cache")
+	if got != want {
+		t.Fatalf(`userCacheDirPath() = %q, want %q`, got, want)
 	}
 }
 
 func Test_UserLibexecDirPath(t *testing.T) {
-	userConfigDir = mockGetUserConfig
+	userConfigDir = mockUserPath
 	setup()
 	got := userLibexecDirPath()
 	if got != "/path/notation" {
 		t.Fatalf(`UserConfigDirPath() = %q, want "/path/notation"`, got)
 	}
 }
 
+func Test_UserCacheDirPath(t *testing.T) {
+	userCacheDir = mockUserPath
+	setup()
+	got := userCacheDirPath()
+	if got != "/path/notation" {
+		t.Fatalf(`UserCacheDirPath() = %q, want "/path/notation"`, got)
+	}
+}
+
 func TestLocalKeyPath(t *testing.T) {
-	userConfigDir = mockGetUserConfig
+	userConfigDir = mockUserPath
 	setup()
 	_ = userConfigDirPath()
 	_ = userLibexecDirPath()
@@ -71,7 +88,7 @@ func TestLocalKeyPath(t *testing.T) {
 }
 
 func TestX509TrustStoreDir(t *testing.T) {
-	userConfigDir = mockGetUserConfig
+	userConfigDir = mockUserPath
 	setup()
 	_ = userConfigDirPath()
 	_ = userLibexecDirPath()

go.mod

@@ -4,7 +4,7 @@ go 1.22.0
 
 require (
 	github.com/go-ldap/ldap/v3 v3.4.8
-	github.com/notaryproject/notation-core-go v1.1.1-0.20240918011623-695ea0c1ad1f
+	github.com/notaryproject/notation-core-go v1.1.1-0.20240920045731-0786f51de737
 	github.com/notaryproject/notation-plugin-framework-go v1.0.0
 	github.com/notaryproject/tspclient-go v0.2.0
 	github.com/opencontainers/go-digest v1.0.0

go.sum

@@ -32,8 +32,8 @@ github.com/jcmturner/gokrb5/v8 v8.4.4 h1:x1Sv4HaTpepFkXbt2IkL29DXRf8sOfZXo8eRKh6
 github.com/jcmturner/gokrb5/v8 v8.4.4/go.mod h1:1btQEpgT6k+unzCwX1KdWMEwPPkkgBtP+F6aCACiMrs=
 github.com/jcmturner/rpc/v2 v2.0.3 h1:7FXXj8Ti1IaVFpSAziCZWNzbNuZmnvw/i6CqLNdWfZY=
 github.com/jcmturner/rpc/v2 v2.0.3/go.mod h1:VUJYCIDm3PVOEHw8sgt091/20OJjskO/YJki3ELg/Hc=
-github.com/notaryproject/notation-core-go v1.1.1-0.20240918011623-695ea0c1ad1f h1:TmwJtM3AZ7iQ1LJEbHRPAMRw4hA52/AbVrllSVjCNP0=
-github.com/notaryproject/notation-core-go v1.1.1-0.20240918011623-695ea0c1ad1f/go.mod h1:+6AOh41JPrnVLbW/19SJqdhVHwKgIINBO/np0e7nXJA=
+github.com/notaryproject/notation-core-go v1.1.1-0.20240920045731-0786f51de737 h1:Hp93KBCABE29+6zdS0GTg0T1SXj6qGatJyN1JMvTQqk=
+github.com/notaryproject/notation-core-go v1.1.1-0.20240920045731-0786f51de737/go.mod h1:b/70rA4OgOHlg0A7pb8zTWKJadFO6781zS3a37KHEJQ=
 github.com/notaryproject/notation-plugin-framework-go v1.0.0 h1:6Qzr7DGXoCgXEQN+1gTZWuJAZvxh3p8Lryjn5FaLzi4=
 github.com/notaryproject/notation-plugin-framework-go v1.0.0/go.mod h1:RqWSrTOtEASCrGOEffq0n8pSg2KOgKYiWqFWczRSics=
 github.com/notaryproject/tspclient-go v0.2.0 h1:g/KpQGmyk/h7j60irIRG1mfWnibNOzJ8WhLqAzuiQAQ=

internal/file/file.go

@@ -15,6 +15,7 @@ package file
 
 import (
 	"errors"
+	"fmt"
 	"io"
 	"io/fs"
 	"os"
@@ -23,6 +24,11 @@ import (
 	"strings"
 )
 
+const (
+	// tempFileNamePrefix is the prefix of the temporary file
+	tempFileNamePrefix = "notation-*"
+)
+
 // ErrNotRegularFile is returned when the file is not an regular file.
 var ErrNotRegularFile = errors.New("not regular file")
 
@@ -110,3 +116,31 @@ func CopyDirToDir(src, dst string) error {
 func TrimFileExtension(fileName string) string {
 	return strings.TrimSuffix(fileName, filepath.Ext(fileName))
 }
+
+// WriteFile writes content to a temporary file and moves it to path.
+// If path already exists and is a file, WriteFile overwrites it.
+func WriteFile(path string, content []byte) (writeErr error) {
+	tempFile, err := os.CreateTemp("", tempFileNamePrefix)
+	if err != nil {
+		return fmt.Errorf("failed to create temp file: %w", err)
+	}
+	defer func() {
+		// remove the temp file in case of error
+		if writeErr != nil {
+			tempFile.Close()
+			os.Remove(tempFile.Name())
+		}
+	}()
+
+	if _, err := tempFile.Write(content); err != nil {
+		return fmt.Errorf("failed to write content to temp file: %w", err)
+	}
+
+	// close before moving
+	if err := tempFile.Close(); err != nil {
+		return fmt.Errorf("failed to close temp file: %w", err)
+	}
+
+	// rename is atomic on UNIX-like platforms
+	return os.Rename(tempFile.Name(), path)
+}

internal/file/file_test.go

@@ -18,6 +18,7 @@ import (
 	"os"
 	"path/filepath"
 	"runtime"
+	"strings"
 	"testing"
 )
 
@@ -26,7 +27,10 @@ func TestCopyToDir(t *testing.T) {
 		tempDir := t.TempDir()
 		data := []byte("data")
 		filename := filepath.Join(tempDir, "a", "file.txt")
-		if err := writeFile(filename, data); err != nil {
+		if err := os.MkdirAll(filepath.Dir(filename), 0700); err != nil {
+			t.Fatal(err)
+		}
+		if err := WriteFile(filename, data); err != nil {
 			t.Fatal(err)
 		}
 
@@ -45,7 +49,10 @@ func TestCopyToDir(t *testing.T) {
 		destDir := t.TempDir()
 		data := []byte("data")
 		filename := filepath.Join(tempDir, "a", "file.txt")
-		if err := writeFile(filename, data); err != nil {
+		if err := os.MkdirAll(filepath.Dir(filename), 0700); err != nil {
+			t.Fatal(err)
+		}
+		if err := WriteFile(filename, data); err != nil {
 			t.Fatal(err)
 		}
 
@@ -77,7 +84,10 @@ func TestCopyToDir(t *testing.T) {
 		data := []byte("data")
 		// prepare file
 		filename := filepath.Join(tempDir, "a", "file.txt")
-		if err := writeFile(filename, data); err != nil {
+		if err := os.MkdirAll(filepath.Dir(filename), 0700); err != nil {
+			t.Fatal(err)
+		}
+		if err := WriteFile(filename, data); err != nil {
 			t.Fatal(err)
 		}
 		// forbid reading
@@ -100,7 +110,10 @@ func TestCopyToDir(t *testing.T) {
 		data := []byte("data")
 		// prepare file
 		filename := filepath.Join(tempDir, "a", "file.txt")
-		if err := writeFile(filename, data); err != nil {
+		if err := os.MkdirAll(filepath.Dir(filename), 0700); err != nil {
+			t.Fatal(err)
+		}
+		if err := WriteFile(filename, data); err != nil {
 			t.Fatal(err)
 		}
 		// forbid dest directory operation
@@ -123,7 +136,10 @@ func TestCopyToDir(t *testing.T) {
 		data := []byte("data")
 		// prepare file
 		filename := filepath.Join(tempDir, "a", "file.txt")
-		if err := writeFile(filename, data); err != nil {
+		if err := os.MkdirAll(filepath.Dir(filename), 0700); err != nil {
+			t.Fatal(err)
+		}
+		if err := WriteFile(filename, data); err != nil {
 			t.Fatal(err)
 		}
 		// forbid writing to destTempDir
@@ -140,7 +156,10 @@ func TestCopyToDir(t *testing.T) {
 		tempDir := t.TempDir()
 		data := []byte("data")
 		filename := filepath.Join(tempDir, "a", "file.txt")
-		if err := writeFile(filename, data); err != nil {
+		if err := os.MkdirAll(filepath.Dir(filename), 0700); err != nil {
+			t.Fatal(err)
+		}
+		if err := WriteFile(filename, data); err != nil {
 			t.Fatal(err)
 		}
 
@@ -161,6 +180,29 @@ func TestFileNameWithoutExtension(t *testing.T) {
 	}
 }
 
+func TestWriteFile(t *testing.T) {
+	tempDir := t.TempDir()
+	content := []byte("test WriteFile")
+
+	t.Run("permission denied", func(t *testing.T) {
+		if runtime.GOOS == "windows" {
+			t.Skip("skipping test on Windows")
+		}
+		err := os.Chmod(tempDir, 0)
+		if err != nil {
+			t.Fatal(err)
+		}
+		err = WriteFile(filepath.Join(tempDir, "testFile"), content)
+		if err == nil || !strings.Contains(err.Error(), "permission denied") {
+			t.Fatalf("expected permission denied error, but got %s", err)
+		}
+		err = os.Chmod(tempDir, 0700)
+		if err != nil {
+			t.Fatal(err)
+		}
+	})
+}
+
 func validFileContent(t *testing.T, filename string, content []byte) {
 	b, err := os.ReadFile(filename)
 	if err != nil {
@@ -170,10 +212,3 @@ func validFileContent(t *testing.T, filename string, content []byte) {
 		t.Fatal("file content is not correct")
 	}
 }
-
-func writeFile(path string, data []byte) error {
-	if err := os.MkdirAll(filepath.Dir(path), 0700); err != nil {
-		return err
-	}
-	return os.WriteFile(path, data, 0600)
-}