plan 8: fuzz decoders; fold ẞ and invalid UTF-8 correctly, refuse non-UTF-8 paths in krino new

3 files changed, 60 insertions, 1 deletions

diff --git a/internal/config/fuzz_test.go b/internal/config/fuzz_test.go
new file mode 100644
index 0000000..32926d6
--- /dev/null
+++ b/internal/config/fuzz_test.go
@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package config
+
+import (
+	"fmt"
+	"strconv"
+	"testing"
+	"time"
+)
+
+// FuzzParseSize: a size either fails to parse or is a non-negative number
+// of bytes that reads back the same written as plain digits - no overflow
+// ever wraps a huge size negative.
+func FuzzParseSize(f *testing.F) {
+	for _, s := range []string{"50M", "0", "1T", "9223372036854775807", "8388608T", "8388607T", "-1", "1.5G", "", "G", "007K"} {
+		f.Add(s)
+	}
+	f.Fuzz(func(t *testing.T, s string) {
+		v, err := ParseSize(s)
+		if err != nil {
+			return
+		}
+		if v < 0 {
+			t.Fatalf("ParseSize(%q) = %d, negative", s, v)
+		}
+		if back, err := ParseSize(strconv.FormatInt(v, 10)); err != nil || back != v {
+			t.Fatalf("ParseSize(%q) = %d, which reads back as %d, %v", s, v, back, err)
+		}
+	})
+}
+
+// FuzzParseDuration: a duration either fails to parse or is a non-negative
+// whole number of seconds that reads back the same written in seconds.
+func FuzzParseDuration(f *testing.F) {
+	for _, s := range []string{"30d", "0s", "2m", "1w", "15250284452w", "9223372036s", "d", "", "-1d", "1.5h"} {
+		f.Add(s)
+	}
+	f.Fuzz(func(t *testing.T, s string) {
+		d, err := ParseDuration(s)
+		if err != nil {
+			return
+		}
+		if d < 0 || d%time.Second != 0 {
+			t.Fatalf("ParseDuration(%q) = %v", s, d)
+		}
+		if back, err := ParseDuration(fmt.Sprintf("%ds", d/time.Second)); err != nil || back != d {
+			t.Fatalf("ParseDuration(%q) = %v, which reads back as %v, %v", s, d, back, err)
+		}
+	})
+}
diff --git a/internal/config/skel.go b/internal/config/skel.go
index 65d9f95..ca914e3 100644
--- a/internal/config/skel.go
+++ b/internal/config/skel.go
@@ -10,6 +10,7 @@ import (
 	"io/fs"
 	"os"
 	"path/filepath"
+	"unicode/utf8"
 
 	"krino/internal/sexp"
 	"krino/internal/xdg"
@@ -66,6 +67,11 @@ func NewDir(mainFile, name, path string) (string, error) {
 	if err != nil {
 		return "", err
 	}
+	// The path is written into the new file, and config files are UTF-8
+	// text (the reader refuses anything else).
+	if !utf8.ValidString(abs) {
+		return "", fmt.Errorf("%q is not valid UTF-8; krino's config is UTF-8 text, so rename the directory first", abs)
+	}
 	if fi, err := os.Stat(abs); err != nil || !fi.IsDir() {
 		return "", fmt.Errorf("%s is not a directory", abs)
 	}
diff --git a/internal/config/skel_test.go b/internal/config/skel_test.go
index 476af65..3815336 100644
--- a/internal/config/skel_test.go
+++ b/internal/config/skel_test.go
@@ -5,6 +5,7 @@ package config
 import (
 	"bytes"
 	"errors"
+	"fmt"
 	"io/fs"
 	"os"
 	"path/filepath"
@@ -242,7 +243,7 @@ func TestNewDirErrors(t *testing.T) {
 	home := t.TempDir()
 	t.Setenv("HOME", home)
 	writeFiles(t, home, map[string]string{
-		"krino.conf": `(include "a")`, "dirs/a.conf": `(path "~")`, "x/.keep": "", "f": "",
+		"krino.conf": `(include "a")`, "dirs/a.conf": `(path "~")`, "x/.keep": "", "f": "", "lat\xe9n/.keep": "",
 	})
 	main := filepath.Join(home, "krino.conf")
 	tests := []struct{ name, path, want string }{
@@ -251,6 +252,7 @@ func TestNewDirErrors(t *testing.T) {
 		{"b", "~/f", filepath.Join(home, "f") + " is not a directory"},
 		{"b", "~/missing", filepath.Join(home, "missing") + " is not a directory"},
 		{"a", "~/x", `"a" is already included`},
+		{"b", "~/lat\xe9n", fmt.Sprintf("%q is not valid UTF-8; krino's config is UTF-8 text, so rename the directory first", filepath.Join(home, "lat\xe9n"))},
 	}
 	for _, tt := range tests {
 		if _, err := NewDir(main, tt.name, tt.path); err == nil || err.Error() != tt.want {