1 files changed, 11 insertions, 3 deletions

diff --git a/src/lib/libcrypto/man/BIO_f_buffer.3 b/src/lib/libcrypto/man/BIO_f_buffer.3
index 27baf7270c..a22addfbcb 100644
--- a/src/lib/libcrypto/man/BIO_f_buffer.3
+++ b/src/lib/libcrypto/man/BIO_f_buffer.3
@@ -1,5 +1,5 @@
-.\"     $OpenBSD: BIO_f_buffer.3,v 1.11 2022/03/31 17:27:16 naddy Exp $
-.\"     OpenSSL 9b86974e Mar 19 12:32:14 2016 -0400
+.\" $OpenBSD: BIO_f_buffer.3,v 1.12 2022/12/18 19:35:36 schwarze Exp $
+.\" full merge up to OpenSSL 99d63d46 Oct 26 13:56:48 2016 -0400
 .\"
 .\" This file was written by Dr. Stephen Henson <steve@openssl.org>.
 .\" Copyright (c) 2000, 2010, 2015, 2016 The OpenSSL Project.
@@ -49,7 +49,7 @@
 .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 .\" OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd $Mdocdate: March 31 2022 $
+.Dd $Mdocdate: December 18 2022 $
 .Dt BIO_F_BUFFER 3
 .Os
 .Sh NAME
@@ -159,6 +159,14 @@ such as when removing a buffering BIO using
 .Xr BIO_pop 3 .
 .Xr BIO_flush 3
 may need to be retried if the ultimate source/sink BIO is non-blocking.
+.Pp
+When a chain containing a buffering BIO is copied with
+.Xr BIO_dup_chain 3 ,
+.Fn BIO_set_read_buffer_size
+and
+.Fn BIO_set_write_buffer_size
+are called internally to automatically copy both buffer sizes from the
+original BIO object to the new one.
 .Sh RETURN VALUES
 .Fn BIO_f_buffer
 returns the buffering BIO method.