[nginx] SSL: disabled renegotiation checks with SSL_OP_NO_RENEGOTIATION.

[Maxim Dounin]

details:   http://hg.nginx.org/nginx/rev/e3ba4026c02d
branches:  
changeset: 7356:e3ba4026c02d
user:      Maxim Dounin <mdounin at mdounin.ru>
date:      Fri Sep 21 20:31:32 2018 +0300
description:
SSL: disabled renegotiation checks with SSL_OP_NO_RENEGOTIATION.

Following 7319:dcab86115261, as long as SSL_OP_NO_RENEGOTIATION is
defined, it is OpenSSL library responsibility to prevent renegotiation,
so the checks are meaningless.

Additionally, with TLSv1.3 OpenSSL tends to report SSL_CB_HANDSHAKE_START
at various unexpected moments - notably, on KeyUpdate messages and
when sending tickets.  This change prevents unexpected connection
close on KeyUpdate messages and when finishing handshake with upcoming
early data changes.

diffstat:

 src/event/ngx_event_openssl.c |  10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)

diffs (55 lines):

diff --git a/src/event/ngx_event_openssl.c b/src/event/ngx_event_openssl.c
--- a/src/event/ngx_event_openssl.c
+++ b/src/event/ngx_event_openssl.c
@@ -843,6 +843,8 @@ ngx_ssl_info_callback(const ngx_ssl_conn
     BIO               *rbio, *wbio;
     ngx_connection_t  *c;
 
+#ifndef SSL_OP_NO_RENEGOTIATION
+
     if ((where & SSL_CB_HANDSHAKE_START)
         && SSL_is_server((ngx_ssl_conn_t *) ssl_conn))
     {
@@ -854,6 +856,8 @@ ngx_ssl_info_callback(const ngx_ssl_conn
         }
     }
 
+#endif
+
     if ((where & SSL_CB_ACCEPT_LOOP) == SSL_CB_ACCEPT_LOOP) {
         c = ngx_ssl_get_connection((ngx_ssl_conn_t *) ssl_conn);
 
@@ -1391,6 +1395,7 @@ ngx_ssl_handshake(ngx_connection_t *c)
         c->recv_chain = ngx_ssl_recv_chain;
         c->send_chain = ngx_ssl_send_chain;
 
+#ifndef SSL_OP_NO_RENEGOTIATION
 #if OPENSSL_VERSION_NUMBER < 0x10100000L
 #ifdef SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS
 
@@ -1401,6 +1406,7 @@ ngx_ssl_handshake(ngx_connection_t *c)
 
 #endif
 #endif
+#endif
 
         return NGX_OK;
     }
@@ -1628,6 +1634,8 @@ ngx_ssl_handle_recv(ngx_connection_t *c,
     int        sslerr;
     ngx_err_t  err;
 
+#ifndef SSL_OP_NO_RENEGOTIATION
+
     if (c->ssl->renegotiation) {
         /*
          * disable renegotiation (CVE-2009-3555):
@@ -1650,6 +1658,8 @@ ngx_ssl_handle_recv(ngx_connection_t *c,
         return NGX_ERROR;
     }
 
+#endif
+
     if (n > 0) {
 
         if (c->ssl->saved_write_handler) {