Document the public function SSL_set_SSL_CTX(3) from scratch,

which is undocumented in OpenSSL but mentioned in passing in one
OpenSSL manual page, and which was recently mentioned by jsing@ when
working on SSL_set_ciphersuites(3).
With corrections from and OK inoguchi@.

3 files changed, 72 insertions, 3 deletions

diff --git a/src/lib/libssl/man/Makefile b/src/lib/libssl/man/Makefile
index 0ea04a3077..f8e5cffd59 100644
--- a/src/lib/libssl/man/Makefile
+++ b/src/lib/libssl/man/Makefile
@@ -1,4 +1,4 @@
-# $OpenBSD: Makefile,v 1.67 2020/09/17 08:04:22 schwarze Exp $
+# $OpenBSD: Makefile,v 1.68 2020/09/20 10:20:43 schwarze Exp $
 
 .include <bsd.own.mk>
 
@@ -104,6 +104,7 @@ MAN =	BIO_f_ssl.3 \
         SSL_session_reused.3 \
         SSL_set1_host.3 \
         SSL_set1_param.3 \
+        SSL_set_SSL_CTX.3 \
         SSL_set_bio.3 \
         SSL_set_connect_state.3 \
         SSL_set_fd.3 \
diff --git a/src/lib/libssl/man/SSL_set_SSL_CTX.3 b/src/lib/libssl/man/SSL_set_SSL_CTX.3
new file mode 100644
index 0000000000..567e34f681
--- /dev/null
+++ b/src/lib/libssl/man/SSL_set_SSL_CTX.3
@@ -0,0 +1,67 @@
+.\" $OpenBSD: SSL_set_SSL_CTX.3,v 1.1 2020/09/20 10:20:44 schwarze Exp $
+.\"
+.\" Copyright (c) 2020 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
+.\" copyright notice and this permission notice appear in all copies.
+.\"
+.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+.\"
+.Dd $Mdocdate: September 20 2020 $
+.Dt SSL_SET_SSL_CTX 3
+.Os
+.Sh NAME
+.Nm SSL_set_SSL_CTX
+.Nd associate an SSL connection object with a context
+.Sh SYNOPSIS
+.In openssl/ssl.h
+.Ft SSL_CTX *
+.Fo SSL_set_SSL_CTX
+.Fa "SSL *ssl"
+.Fa "SSL_CTX* ctx"
+.Fc
+.Sh DESCRIPTION
+.Fn SSL_set_SSL_CTX
+causes
+.Fa ssl
+to use the context
+.Fa ctx
+in the future.
+.Pp
+If
+.Fa ctx
+is
+.Dv NULL ,
+.Fa ssl
+reverts to using the context that it was initially created from with
+.Xr SSL_new 3 .
+.Pp
+If
+.Fa ssl
+already uses
+.Fa ctx ,
+no action occurs.
+.Sh RETURN VALUES
+.Fn SSL_set_SSL_CTX
+returns an internal pointer to the context that
+.Fa ssl
+will use after the call, or
+.Dv NULL
+if memory allocation fails.
+.Sh SEE ALSO
+.Xr ssl 3 ,
+.Xr SSL_clear 3 ,
+.Xr SSL_CTX_new 3 ,
+.Xr SSL_get_SSL_CTX 3 ,
+.Xr SSL_new 3
+.Sh HISTORY
+.Fn SSL_set_SSL_CTX
+first appeared in OpenSSL 0.9.8f and has been available since
+.Ox 4.5 .
diff --git a/src/lib/libssl/man/ssl.3 b/src/lib/libssl/man/ssl.3
index 0833a52f86..26596a5f8c 100644
--- a/src/lib/libssl/man/ssl.3
+++ b/src/lib/libssl/man/ssl.3
@@ -1,4 +1,4 @@
-.\" $OpenBSD: ssl.3,v 1.18 2020/09/18 15:39:37 schwarze Exp $
+.\" $OpenBSD: ssl.3,v 1.19 2020/09/20 10:20:44 schwarze Exp $
 .\" full merge up to: OpenSSL e330f55d Nov 11 00:51:04 2016 +0100
 .\" selective merge up to: OpenSSL 322755cc Sep 1 08:40:51 2018 +0800
 .\"
@@ -51,7 +51,7 @@
 .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 .\" OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd $Mdocdate: September 18 2020 $
+.Dd $Mdocdate: September 20 2020 $
 .Dt SSL 3
 .Os
 .Sh NAME
@@ -295,6 +295,7 @@ Constructors and destructors:
 .Pp
 To change the configuration:
 .Xr SSL_clear 3 ,
+.Xr SSL_set_SSL_CTX 3 ,
 .Xr SSL_copy_session_id 3 ,
 .Xr SSL_set_bio 3 ,
 .Xr SSL_set_connect_state 3 ,