acme/autocert: properly clean DirCache paths
Don't assume the path passed into the DirCache methods is absolute, and
clean it before further operating on it. Put and Delete are not attacker
controlled, but clean them anyway.
Fixes #53082
Fixes CVE-2022-30636
Change-Id: I755f525a737da60ccba07ebce4d41cc8faebfcca
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/408694
Run-TryBot: Roland Shoemaker <roland@golang.org>
Reviewed-by: Damien Neil <dneil@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
diff --git a/acme/autocert/cache.go b/acme/autocert/cache.go
index 03f6302..3156a08 100644
--- a/acme/autocert/cache.go
+++ b/acme/autocert/cache.go
@@ -41,7 +41,7 @@
// Get reads a certificate data from the specified file name.
func (d DirCache) Get(ctx context.Context, name string) ([]byte, error) {
- name = filepath.Join(string(d), name)
+ name = filepath.Join(string(d), filepath.Clean("/"+name))
var (
data []byte
err error
@@ -82,7 +82,7 @@
case <-ctx.Done():
// Don't overwrite the file if the context was canceled.
default:
- newName := filepath.Join(string(d), name)
+ newName := filepath.Join(string(d), filepath.Clean("/"+name))
err = os.Rename(tmp, newName)
}
}()
@@ -96,7 +96,7 @@
// Delete removes the specified file name.
func (d DirCache) Delete(ctx context.Context, name string) error {
- name = filepath.Join(string(d), name)
+ name = filepath.Join(string(d), filepath.Clean("/"+name))
var (
err error
done = make(chan struct{})
