Apply a little bit of lipstick to PKCS7

Makes the setting and getting of detached signatures more symmetric
and avoids a NULL access.

ok jsing

1 files changed, 7 insertions, 3 deletions

diff --git a/src/lib/libcrypto/pkcs7/pk7_lib.c b/src/lib/libcrypto/pkcs7/pk7_lib.c
index 59f348e234..aa48c269ea 100644
--- a/src/lib/libcrypto/pkcs7/pk7_lib.c
+++ b/src/lib/libcrypto/pkcs7/pk7_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: pk7_lib.c,v 1.28 2023/11/09 19:08:07 tb Exp $ */
+/* $OpenBSD: pk7_lib.c,v 1.29 2024/12/05 07:35:46 tb Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -70,13 +70,17 @@ long
 PKCS7_ctrl(PKCS7 *p7, int cmd, long larg, char *parg)
 {
         int nid;
-        long ret;
+        long ret = 0;
 
         nid = OBJ_obj2nid(p7->type);
 
         switch (cmd) {
         case PKCS7_OP_SET_DETACHED_SIGNATURE:
                 if (nid == NID_pkcs7_signed) {
+                        if (p7->d.sign == NULL) {
+                                PKCS7error(PKCS7_R_NO_CONTENT);
+                                break;
+                        }
                         ret = p7->detached = (int)larg;
                         if (ret && PKCS7_type_is_data(p7->d.sign->contents)) {
                                 ASN1_OCTET_STRING *os;
@@ -91,7 +95,7 @@ PKCS7_ctrl(PKCS7 *p7, int cmd, long larg, char *parg)
                 break;
         case PKCS7_OP_GET_DETACHED_SIGNATURE:
                 if (nid == NID_pkcs7_signed) {
-                        if (!p7->d.sign  || !p7->d.sign->contents->d.ptr)
+                        if (p7->d.sign  || !p7->d.sign->contents->d.ptr)
                                 ret = 1;
                         else
                                 ret = 0;