Add SSL_CTX_set_keylog_callback and SSL_CTX_get_keylog_callback

Some things in ports care about calling these functions. Since we will
not provide private key logging functionality they are documented
as being for compatibility and that they don't do anything.

ok tb@

src/lib/libssl/man/Makefile

@@ -1,4 +1,4 @@
-# $OpenBSD: Makefile,v 1.73 2021/09/14 14:30:57 schwarze Exp $
+# $OpenBSD: Makefile,v 1.74 2021/10/23 11:41:52 beck Exp $
 
 .include <bsd.own.mk>
 
@@ -32,6 +32,7 @@ MAN =	BIO_f_ssl.3 \
 	SSL_CTX_set_default_passwd_cb.3 \
 	SSL_CTX_set_generate_session_id.3 \
 	SSL_CTX_set_info_callback.3 \
+	SSL_CTX_set_keylog_callback.3 \
 	SSL_CTX_set_max_cert_list.3 \
 	SSL_CTX_set_min_proto_version.3 \
 	SSL_CTX_set_mode.3 \

src/lib/libssl/man/SSL_CTX_set_keylog_callback.3

@@ -0,0 +1,44 @@
+.\" $OpenBSD: SSL_CTX_set_keylog_callback.3,v 1.1 2021/10/23 11:41:52 beck Exp $
+.\" Copyright (c) 2021, Bob Beck <beck@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: October 23 2021 $
+.Dt SSL_CTX_SET_KEYLOG_CALLBACK 3
+.Os
+.Sh NAME
+.Nm SSL_CTX_set_keylog_callback ,
+.Nm SSL_CTX_get_keylog_callback
+.Nd set and get the unused key logging callback
+.Sh SYNOPSIS
+.In openssl/ssl.h
+.Bd -literal
+typedef void (*SSL_CTX_keylog_cb_func)(const SSL *ssl, const char *line)
+.Ed
+.Ft void
+.Fn SSL_CTX_set_keylog_callback "SSL_CTX *ctx" "SSL_CTX_keylog_cb_func cb"
+.Ft SSL_CTX_keylog_cb_func
+.Fn SSL_CTX_get_keylog_callback "const SSL_CTX *ctx"
+.Sh DESCRIPTION
+.Fn SSL_CTX_set_keylog_callback
+sets the TLS key logging callback.
+This callback is never called in LibreSSL.
+.Pp
+.Fn SSL_CTX_set_keylog_callback
+retrieves the previously set TLS key logging callback.
+.Pp
+These functions are provided only for compatibility with OpenSSL.
+.Sh RETURN VALUES
+.Fn SSL_CTX_get_keylog_callback
+returns the previously set TLS key logging callback, or NULL
+if no callback has been set.

src/lib/libssl/ssl.h

@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl.h,v 1.210 2021/10/15 16:48:46 jsing Exp $ */
+/* $OpenBSD: ssl.h,v 1.211 2021/10/23 11:41:51 beck Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -505,6 +505,11 @@ void SSL_set_msg_callback(SSL *ssl, void (*cb)(int write_p, int version,
     int content_type, const void *buf, size_t len, SSL *ssl, void *arg));
 #define SSL_CTX_set_msg_callback_arg(ctx, arg) SSL_CTX_ctrl((ctx), SSL_CTRL_SET_MSG_CALLBACK_ARG, 0, (arg))
 #define SSL_set_msg_callback_arg(ssl, arg) SSL_ctrl((ssl), SSL_CTRL_SET_MSG_CALLBACK_ARG, 0, (arg))
+typedef void (*SSL_CTX_keylog_cb_func)(const SSL *ssl, const char *line);
+#if defined(LIBRESSL_NEW_API)
+void SSL_CTX_set_keylog_callback(SSL_CTX *ctx, SSL_CTX_keylog_cb_func cb);
+SSL_CTX_keylog_cb_func SSL_CTX_get_keylog_callback(const SSL_CTX *ctx);
+#endif
 
 #ifndef LIBRESSL_INTERNAL
 struct ssl_aead_ctx_st;

src/lib/libssl/ssl_lib.c

@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_lib.c,v 1.268 2021/09/10 08:59:56 tb Exp $ */
+/* $OpenBSD: ssl_lib.c,v 1.269 2021/10/23 11:41:52 beck Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -770,6 +770,18 @@ int
 	return (s->internal->verify_callback);
 }
 
+void
+SSL_CTX_set_keylog_callback(SSL_CTX *ctx, SSL_CTX_keylog_cb_func cb)
+{
+	ctx->internal->keylog_callback = cb;
+}
+
+SSL_CTX_keylog_cb_func
+SSL_CTX_get_keylog_callback(const SSL_CTX *ctx)
+{
+	return (ctx->internal->keylog_callback);
+}
+
 int
 SSL_CTX_get_verify_mode(const SSL_CTX *ctx)
 {

src/lib/libssl/ssl_locl.h

@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_locl.h,v 1.361 2021/10/23 08:34:36 jsing Exp $ */
+/* $OpenBSD: ssl_locl.h,v 1.362 2021/10/23 11:41:52 beck Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -843,6 +843,7 @@ typedef struct ssl_ctx_internal_st {
 	uint8_t *tlsext_ecpointformatlist; /* our list */
 	size_t tlsext_supportedgroups_length;
 	uint16_t *tlsext_supportedgroups; /* our list */
+	SSL_CTX_keylog_cb_func keylog_callback; /* Unused. For OpenSSL compatibility. */
 } SSL_CTX_INTERNAL;
 
 struct ssl_ctx_st {