FileStorage: Fix List(); modify Storage interface (fixes #4)

Adding a recursive option to List(), which, if true, causes List to
act like a walk function.

Also differentiating between "terminal" keys and "non-terminal" in
KeyInfo, since sometimes directories are useful, like listing user
accounts.

filestorage.go

@@ -18,6 +18,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
+	"path"
 	"path/filepath"
 	"runtime"
 	"sync"
@@ -67,16 +68,34 @@ func (fs FileStorage) Delete(key string) error {
 }
 
 // List returns all keys that match prefix.
-func (fs FileStorage) List(prefix string) ([]string, error) {
-	d, err := os.Open(fs.Filename(prefix))
-	if os.IsNotExist(err) {
-		return nil, ErrNotExist(err)
-	}
-	if err != nil {
-		return nil, err
-	}
-	defer d.Close()
-	return d.Readdirnames(-1)
+func (fs FileStorage) List(prefix string, recursive bool) ([]string, error) {
+	var keys []string
+	walkPrefix := fs.Filename(prefix)
+
+	err := filepath.Walk(walkPrefix, func(fpath string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+		if info == nil {
+			return fmt.Errorf("%s: file info is nil", fpath)
+		}
+		if fpath == walkPrefix {
+			return nil
+		}
+
+		suffix, err := filepath.Rel(walkPrefix, fpath)
+		if err != nil {
+			return fmt.Errorf("%s: could not make path relative: %v", fpath, err)
+		}
+		keys = append(keys, path.Join(prefix, suffix))
+
+		if !recursive && info.IsDir() {
+			return filepath.SkipDir
+		}
+		return nil
+	})
+
+	return keys, err
 }
 
 // Stat returns information about key.
@@ -89,9 +108,10 @@ func (fs FileStorage) Stat(key string) (KeyInfo, error) {
 		return KeyInfo{}, err
 	}
 	return KeyInfo{
-		Key:      key,
-		Modified: fi.ModTime(),
-		Size:     fi.Size(),
+		Key:        key,
+		Modified:   fi.ModTime(),
+		Size:       fi.Size(),
+		IsTerminal: !fi.IsDir(),
 	}, nil
 }
 

maintain.go

@@ -261,7 +261,7 @@ func (certCache *Cache) updateOCSPStaples() {
 // deleteOldStapleFiles deletes cached OCSP staples that have expired.
 // TODO: We should do this for long-expired certificates, too.
 func (certCache *Cache) deleteOldStapleFiles() {
-	ocspKeys, err := certCache.storage.List(prefixOCSP)
+	ocspKeys, err := certCache.storage.List(prefixOCSP, false)
 	if err != nil {
 		// maybe just hasn't been created yet; no big deal
 		return

storage.go

@@ -49,7 +49,11 @@ type Storage interface {
 	Exists(key string) bool
 
 	// List returns all keys that match prefix.
-	List(prefix string) ([]string, error)
+	// If recursive is true, non-terminal keys
+	// will be enumerated (i.e. "directories"
+	// should be walked); otherwise, only keys
+	// prefixed exactly by prefix will be listed.
+	List(prefix string, recursive bool) ([]string, error)
 
 	// Stat returns information about key.
 	Stat(key string) (KeyInfo, error)
@@ -92,9 +96,10 @@ type Waiter interface {
 
 // KeyInfo holds information about a key in storage.
 type KeyInfo struct {
-	Key      string
-	Modified time.Time
-	Size     int64
+	Key        string
+	Modified   time.Time
+	Size       int64
+	IsTerminal bool // false for keys that only contain other keys (like directories)
 }
 
 // storeTx stores all the values or none at all.

user.go

@@ -24,6 +24,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"path"
 	"sort"
 	"strings"
 
@@ -240,16 +241,16 @@ func (cfg *Config) askUserAgreement(agreementURL string) bool {
 // account, errors here are discarded to simplify code flow in
 // the caller, and errors are not important here anyway.
 func (cfg *Config) mostRecentUserEmail() string {
-	userList, err := cfg.certCache.storage.List(StorageKeys.UsersPrefix(cfg.CA))
+	userList, err := cfg.certCache.storage.List(StorageKeys.UsersPrefix(cfg.CA), false)
 	if err != nil || len(userList) == 0 {
 		return ""
 	}
 	sort.Slice(userList, func(i, j int) bool {
-		iInfo, _ := cfg.certCache.storage.Stat(StorageKeys.UserPrefix(cfg.CA, userList[i]))
-		jInfo, _ := cfg.certCache.storage.Stat(StorageKeys.UserPrefix(cfg.CA, userList[j]))
+		iInfo, _ := cfg.certCache.storage.Stat(userList[i])
+		jInfo, _ := cfg.certCache.storage.Stat(userList[j])
 		return jInfo.Modified.Before(iInfo.Modified)
 	})
-	user, err := cfg.getUser(userList[0])
+	user, err := cfg.getUser(path.Base(userList[0]))
 	if err != nil {
 		return ""
 	}