From: Matt Caswell <matt@openssl.org>
Date: Wed, 8 Nov 2017 15:00:48 +0000 (+0000)
Subject: Send a CCS after ServerHello in TLSv1.3 if using middlebox compat mode
X-Git-Tag: OpenSSL_1_1_1-pre1~289
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=db37d32cb89160328b0ba48e3808f601a7b3ebe8;p=openssl

Send a CCS after ServerHello in TLSv1.3 if using middlebox compat mode

Reviewed-by: Ben Kaduk <kaduk@mit.edu>
(Merged from https://github.com/openssl/openssl/pull/4701)
---

diff --git a/ssl/ssl_conf.c b/ssl/ssl_conf.c
index 0f53a47043..0cd8ace437 100644
--- a/ssl/ssl_conf.c
+++ b/ssl/ssl_conf.c
@@ -592,7 +592,7 @@ static const ssl_conf_cmd_tbl ssl_conf_cmds[] = {
     SSL_CONF_CMD_SWITCH("allow_no_dhe_kex", 0),
     SSL_CONF_CMD_SWITCH("prioritize_chacha", SSL_CONF_FLAG_SERVER),
     SSL_CONF_CMD_SWITCH("strict", 0),
-    SSL_CONF_CMD_SWITCH("no_middlebox", SSL_CONF_FLAG_CLIENT),
+    SSL_CONF_CMD_SWITCH("no_middlebox", 0),
     SSL_CONF_CMD_STRING(SignatureAlgorithms, "sigalgs", 0),
     SSL_CONF_CMD_STRING(ClientSignatureAlgorithms, "client_sigalgs", 0),
     SSL_CONF_CMD_STRING(Curves, "curves", 0),
diff --git a/ssl/statem/statem_srvr.c b/ssl/statem/statem_srvr.c
index 36083096b9..43ad4a4623 100644
--- a/ssl/statem/statem_srvr.c
+++ b/ssl/statem/statem_srvr.c
@@ -403,6 +403,13 @@ static WRITE_TRAN ossl_statem_server13_write_transition(SSL *s)
         return WRITE_TRAN_CONTINUE;
 
     case TLS_ST_SW_SRVR_HELLO:
+        if ((s->options & SSL_OP_ENABLE_MIDDLEBOX_COMPAT) != 0)
+            st->hand_state = TLS_ST_SW_CHANGE;
+        else
+            st->hand_state = TLS_ST_SW_ENCRYPTED_EXTENSIONS;
+        return WRITE_TRAN_CONTINUE;
+
+    case TLS_ST_SW_CHANGE:
         st->hand_state = TLS_ST_SW_ENCRYPTED_EXTENSIONS;
         return WRITE_TRAN_CONTINUE;
 
@@ -763,6 +770,12 @@ WORK_STATE ossl_statem_server_post_work(SSL *s, WORK_STATE wst)
                      sizeof(sctpauthkey), sctpauthkey);
         }
 #endif
+        if (!SSL_IS_TLS13(s)
+                || (s->options & SSL_OP_ENABLE_MIDDLEBOX_COMPAT) != 0)
+            break;
+        /* Fall through */
+
+    case TLS_ST_SW_CHANGE:
         /*
          * TODO(TLS1.3): This actually causes a problem. We don't yet know
          * whether the next record we are going to receive is an unencrypted
@@ -783,10 +796,9 @@ WORK_STATE ossl_statem_server_post_work(SSL *s, WORK_STATE wst)
                 /* SSLfatal() already called */
                 return WORK_ERROR;
             }
+            break;
         }
-        break;
 
-    case TLS_ST_SW_CHANGE:
 #ifndef OPENSSL_NO_SCTP
         if (SSL_IS_DTLS(s) && !s->hit) {
             /*