t.Fatalf("test %d, unknown test operation: %T", i, tf)
				}
			}

			if v.file != "" {
				path := v.file
				if v.obscured {
					tf, err := obscuretestdata.DecodeToTempFile(path)
					if err != nil {
						t.Fatalf("obscuretestdata.DecodeToTempFile(%s): %v", path, err)
					}
					path = tf
				}

				want, err := os.ReadFile(path)
				if err != nil {
					t.Fatalf("ReadFile() = %v, want nil", err)

	for _, v := range vectors {
		t.Run(strings.TrimSuffix(path.Base(v.file), ".base64"), func(t *testing.T) {
			path := v.file
			if v.obscured {
				tf, err := obscuretestdata.DecodeToTempFile(path)
				if err != nil {
					t.Fatalf("obscuredtestdata.DecodeToTempFile(%s): %v", path, err)
				}
				path = tf
			}

			f, err := os.Open(path)
			if err != nil {
				t.Fatalf("unexpected error: %v", err)
			}

			t.Errorf("ReadAt error=%v", err)
			return
		}
	} else {
		path := filepath.Join("testdata", zt.Name)
		if zt.Obscured {
			tf, err := obscuretestdata.DecodeToTempFile(path)
			if err != nil {
				t.Errorf("obscuretestdata.DecodeToTempFile(%s): %v", path, err)
				return
			}
			defer os.Remove(tf)
			path = tf
		}
		var rc *ReadCloser
		rc, err = OpenReader(path)
		if err == nil {