Clean up wrong vanity rules

internal/store/id.go

@@ -13,15 +13,6 @@ import (
 // could be mistaken for a path element, a dotfile or a traversal is excluded.
 var vanityRe = regexp.MustCompile(`^[a-z0-9][a-z0-9._-]{1,63}$`)
 
-// reserved names would shadow a route or a well-known file if they were ever
-// allowed into the object namespace.
-var reserved = map[string]bool{
-	"d": true, "i": true, "api": true, "static": true, "admin": true,
-	"login": true, "logout": true, "upload": true,
-	"favicon.ico": true, "robots.txt": true, "index.html": true,
-	"sitemap.xml": true, "tokens.json": true, "objects": true,
-}
-
 var ErrBadID = errors.New("invalid name")
 
 // CleanID validates an id arriving from a URL or from a vanity request and
@@ -30,6 +21,12 @@ var ErrBadID = errors.New("invalid name")
 //
 // This is the *only* function permitted to turn caller input into a path
 // element; every filesystem path in this package is built from its output.
+//
+// There is deliberately no list of reserved words. An id appears only under
+// /d/ and /i/ in a URL, and only as a directory of its own inside the objects
+// directory on disk, so no spelling of it can shadow a route or a file of
+// ours: "favicon.png" and "admin" are ordinary names and refusing them would
+// be theatre.
 func CleanID(s string) (string, error) {
 	s = strings.ToLower(strings.TrimSpace(s))
 	if !vanityRe.MatchString(s) {
@@ -40,9 +37,6 @@ func CleanID(s string) (string, error) {
 	if strings.Contains(s, "..") || strings.HasSuffix(s, ".") {
 		return "", ErrBadID
 	}
-	if reserved[s] {
-		return "", ErrBadID
-	}
 	return s, nil
 }
 

internal/store/store_test.go

@@ -23,12 +23,11 @@ func TestCleanID(t *testing.T) {
 		}
 	}
 
-	// Anything that could escape the objects directory, shadow a route, or
-	// collide on a case-insensitive filesystem must be refused.
+	// Anything that could escape the objects directory or collide on a
+	// case-insensitive filesystem must be refused.
 	invalid := []string{
 		"", "a", ".", "..", "...", "../etc/passwd", "a/b", `a\b`, "/abs",
-		".hidden", "a..b", "trailing.", "api", "static", "d", "i",
-		"robots.txt", "tokens.json", "with space", "emoji-🙂",
+		".hidden", "a..b", "trailing.", "d", "i", "with space", "emoji-🙂",
 		strings.Repeat("x", 65), "a\x00b", "a\nb",
 	}
 	for _, in := range invalid {
@@ -36,6 +35,16 @@ func TestCleanID(t *testing.T) {
 			t.Errorf("CleanID(%q) = %q, want an error", in, got)
 		}
 	}
+
+	// Names that merely look like something of ours are ordinary names: an id
+	// lives under /d/ and /i/ and in a directory of its own, so it shadows
+	// nothing. Refusing these would take names from people for no benefit.
+	for _, in := range []string{"api", "static", "admin", "upload", "login",
+		"robots.txt", "tokens.json", "favicon.png", "index.html"} {
+		if got, err := CleanID(in); err != nil || got != in {
+			t.Errorf("CleanID(%q) = %q, %v; want it accepted unchanged", in, got, err)
+		}
+	}
 }
 
 func TestCleanIDAcceptsGeneratedUUIDs(t *testing.T) {