CMS_sign expects certstack to be a pointer

diff --git a/ctypescrypto/cms.py b/ctypescrypto/cms.py
index c4ee1e9e1e2fbc04c09a9f387ea0ab9deeb4bb0b..ede20f5e631bad5d346f90391cde2c97371985f2 100644 (file)
--- a/ctypescrypto/cms.py
+++ b/ctypescrypto/cms.py
@@ -120,7 +120,7 @@ class SignedData(CMSBase):
             raise ValueError("Certificate doesn't match public key")
         bio = Membio(data)
         if certs is not None and len(certs) > 0:
-            certstack = StackOfX509(certs)
+            certstack = StackOfX509(certs).ptr
         else:
             certstack = None
         ptr = libcrypto.CMS_sign(cert.cert, pkey.key, certstack, bio.bio, flags)