1 files changed, 12 insertions, 3 deletions

diff --git a/src/lib/libcrypto/asn1/a_object.c b/src/lib/libcrypto/asn1/a_object.c
index aae1b8bbd7..ed9e9287c4 100644
--- a/src/lib/libcrypto/asn1/a_object.c
+++ b/src/lib/libcrypto/asn1/a_object.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: a_object.c,v 1.53 2024/05/29 16:10:41 tb Exp $ */
+/* $OpenBSD: a_object.c,v 1.54 2024/05/29 16:14:38 tb Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -615,7 +615,7 @@ c2i_ASN1_OBJECT(ASN1_OBJECT **out_aobj, const unsigned char **pp, long len)
 int
 i2d_ASN1_OBJECT(const ASN1_OBJECT *a, unsigned char **pp)
 {
-        unsigned char *p;
+        unsigned char *buf, *p;
         int objsize;
 
         if (a == NULL || a->data == NULL)
@@ -626,11 +626,20 @@ i2d_ASN1_OBJECT(const ASN1_OBJECT *a, unsigned char **pp)
         if (pp == NULL)
                 return objsize;
 
-        p = *pp;
+        if ((buf = *pp) == NULL)
+                buf = calloc(1, objsize);
+        if (buf == NULL)
+                return -1;
+
+        p = buf;
         ASN1_put_object(&p, 0, a->length, V_ASN1_OBJECT, V_ASN1_UNIVERSAL);
         memcpy(p, a->data, a->length);
         p += a->length;
 
+        /* If buf was allocated, return it, otherwise return the advanced p. */
+        if (*pp == NULL)
+                p = buf;
+
         *pp = p;
 
         return objsize;