Add SSL_get[01]_peer_certificate()

Deprecate SSL_get_peer_certificte() and replace with
SSL_get1_peer_certificate().
Add SSL_get0_peer_certificate.

Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
Reviewed-by: Tomas Mraz <tmraz@fedoraproject.org>
(Merged from https://github.com/openssl/openssl/pull/8730)

1 files changed, 21 insertions, 6 deletions

diff --git a/doc/man3/SSL_get_peer_certificate.pod b/doc/man3/SSL_get_peer_certificate.pod
index e21e3e4fd4..b695edc689 100644
--- a/doc/man3/SSL_get_peer_certificate.pod
+++ b/doc/man3/SSL_get_peer_certificate.pod
@@ -2,17 +2,21 @@
 
 =head1 NAME
 
-SSL_get_peer_certificate - get the X509 certificate of the peer
+SSL_get_peer_certificate,
+SSL_get0_peer_certificate,
+SSL_get1_peer_certificate - get the X509 certificate of the peer
 
 =head1 SYNOPSIS
 
  #include <openssl/ssl.h>
 
  X509 *SSL_get_peer_certificate(const SSL *ssl);
+ X509 *SSL_get0_peer_certificate(const SSL *ssl);
+ X509 *SSL_get1_peer_certificate(const SSL *ssl);
 
 =head1 DESCRIPTION
 
-SSL_get_peer_certificate() returns a pointer to the X509 certificate the
+These functions return a pointer to the X509 certificate the
 peer presented. If the peer did not present a certificate, NULL is returned.
 
 =head1 NOTES
@@ -27,9 +31,15 @@ That a certificate is returned does not indicate information about the
 verification state, use L<SSL_get_verify_result(3)>
 to check the verification state.
 
-The reference count of the X509 object is incremented by one, so that it
-will not be destroyed when the session containing the peer certificate is
-freed. The X509 object must be explicitly freed using X509_free().
+The reference count of the X509 object returned by SSL_get1_peer_certificate()
+is incremented by one, so that it will not be destroyed when the session
+containing the peer certificate is freed. The X509 object must be explicitly
+freed using X509_free().
+
+The reference count of the X509 object returned by SSL_get0_peer_certificate()
+is not incremented, and must not be freed.
+
+SSL_get_peer_certificate() is an alias of SSL_get1_peer_certificate().
 
 =head1 RETURN VALUES
 
@@ -52,9 +62,14 @@ The return value points to the certificate presented by the peer.
 L<ssl(7)>, L<SSL_get_verify_result(3)>,
 L<SSL_CTX_set_verify(3)>
 
+=head1 HISTORY
+
+SSL_get0_peer_certificate() and SSL_get1_peer_certificate() were added in 3.0.0.
+SSL_get_peer_certificate() was deprecated in 3.0.0.
+
 =head1 COPYRIGHT
 
-Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
+Copyright 2000-2020 The OpenSSL Project Authors. All Rights Reserved.
 
 Licensed under the Apache License 2.0 (the "License").  You may not use
 this file except in compliance with the License.  You can obtain a copy