Given asn1/a_object.c rev. 1.45 by jsing@, stop talking about BUGS

we no longer have, focus on what our implementation now does, but
keep short warnings in how far other implementations might be more
fragile.  Some improvements to wordings and clarity while here.
OK tb@

Author: schwarze

src/lib/libcrypto/man/d2i_ASN1_OBJECT.3

@@ -1,7 +1,6 @@
-.\"	$OpenBSD: d2i_ASN1_OBJECT.3,v 1.11 2021/12/08 13:21:04 schwarze Exp $
-.\"	OpenSSL 05ea606a May 20 20:52:46 2016 -0400
+.\" $OpenBSD: d2i_ASN1_OBJECT.3,v 1.12 2022/03/29 17:41:20 schwarze Exp $
 .\"
-.\" Copyright (c) 2017 Ingo Schwarze <schwarze@openbsd.org>
+.\" Copyright (c) 2017, 2022 Ingo Schwarze <schwarze@openbsd.org>
 .\"
 .\" Permission to use, copy, modify, and distribute this software for any
 .\" purpose with or without fee is hereby granted, provided that the above
@@ -15,7 +14,7 @@
 .\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 .\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: December 8 2021 $
+.Dd $Mdocdate: March 29 2022 $
 .Dt D2I_ASN1_OBJECT 3
 .Os
 .Sh NAME
@@ -42,32 +41,36 @@ These functions decode and encode ASN.1 object identifiers.
 For details about the semantics, examples, caveats, and bugs, see
 .Xr ASN1_item_d2i 3 .
 .Pp
+The LibreSSL implementation of
+.Fn d2i_ASN1_OBJECT
+always calls
+.Xr ASN1_OBJECT_free 3
+if an existing object is passed in via
+.Fa val_out
+and it always creates a new object from scratch.
+Other implementations may attempt to reuse an existing object,
+which is fragile and prone to bugs.
+Consequently, always passing
+.Dv NULL
+for the
+.Fa val_out
+argument is recommended.
+.Pp
 The objects returned from
 .Fn d2i_ASN1_OBJECT
 and the data contained in them are always marked as dynamically
 allocated, so when they are no longer needed,
 .Xr ASN1_OBJECT_free 3
 can be called on them.
-.Pp
-If reusing an existing object is attempted but the
-.Pf * Fa val_out
-passed in points to an object that is not marked as dynamically
-allocated, then the existing object is left untouched and
-.Fn d2i_ASN1_OBJECT
-behaves as if
-.Pf * Fa val_out
-would have been
-.Dv NULL :
-A new object is allocated and a pointer to it is both stored in
-.Pf * Fa val_out
-and returned.
 .Sh RETURN VALUES
 .Fn d2i_ASN1_OBJECT
-returns an
+returns a pointer to the new
 .Vt ASN1_OBJECT
 object or
 .Dv NULL
 if an error occurs.
+With other implementations, it might return a pointer to the reused
+.Vt ASN1_OBJECT .
 .Pp
 .Fn i2d_ASN1_OBJECT
 returns the number of bytes successfully encoded
@@ -101,7 +104,3 @@ on the returned object, and then
 and
 .Xr OBJ_nid2ln 3
 on the result.
-.Sh BUGS
-When reusing a dynamically allocated object that contains dynamically
-allocated names, the old names are not freed and the memory containing
-them is leaked.