Split ServerHello extensions

In TLS1.3 some ServerHello extensions remain in the ServerHello, while
others move to the EncryptedExtensions message. This commit performs that
move.

Perl changes reviewed by Richard Levitte. Non-perl changes reviewed by Rich
Salz

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>

2 files changed, 34 insertions, 30 deletions

diff --git a/ssl/statem/statem_clnt.c b/ssl/statem/statem_clnt.c
index aa1e6e1a89..c47c9aa518 100644
--- a/ssl/statem/statem_clnt.c
+++ b/ssl/statem/statem_clnt.c
@@ -1064,6 +1064,7 @@ MSG_PROCESS_RETURN tls_process_server_hello(SSL *s, PACKET *pkt)
     int i, al = SSL_AD_INTERNAL_ERROR;
     unsigned int compression;
     unsigned int sversion;
+    unsigned int context;
     int protverr;
     RAW_EXTENSION *extensions = NULL;
 #ifndef OPENSSL_NO_COMP
@@ -1306,24 +1307,10 @@ MSG_PROCESS_RETURN tls_process_server_hello(SSL *s, PACKET *pkt)
         goto f_err;
     }
 
-    /*
-     * TODO(TLS1.3): We give multiple contexts for now until we're ready to
-     * give something more specific
-     */
-
-    if (!tls_collect_extensions(s, &extpkt, EXT_TLS1_2_SERVER_HELLO
-                                            | EXT_TLS1_3_SERVER_HELLO
-                                            | EXT_TLS1_3_ENCRYPTED_EXTENSIONS
-                                            | EXT_TLS1_3_CERTIFICATE,
-                                &extensions, &al))
-        goto f_err;
-
-
-    if (!tls_parse_all_extensions(s, EXT_TLS1_2_SERVER_HELLO
-                                     | EXT_TLS1_3_SERVER_HELLO
-                                     | EXT_TLS1_3_ENCRYPTED_EXTENSIONS
-                                     | EXT_TLS1_3_CERTIFICATE,
-                                  extensions, &al))
+    context = SSL_IS_TLS13(s) ? EXT_TLS1_3_SERVER_HELLO
+                              : EXT_TLS1_2_SERVER_HELLO;
+    if (!tls_collect_extensions(s, &extpkt, context, &extensions, &al)
+            || !tls_parse_all_extensions(s, context, extensions, &al))
         goto f_err;
 
 #ifndef OPENSSL_NO_SCTP
@@ -3108,14 +3095,28 @@ static MSG_PROCESS_RETURN tls_process_encrypted_extensions(SSL *s, PACKET *pkt)
 {
     int al = SSL_AD_INTERNAL_ERROR;
     PACKET extensions;
+    RAW_EXTENSION *rawexts = NULL;
 
-    /* TODO(TLS1.3): We need to process these extensions. For now ignore them */
     if (!PACKET_as_length_prefixed_2(pkt, &extensions)) {
         al = SSL_AD_DECODE_ERROR;
         SSLerr(SSL_F_TLS_PROCESS_ENCRYPTED_EXTENSIONS, SSL_R_LENGTH_MISMATCH);
         goto err;
     }
 
+    /*
+     * TODO(TLS1.3): For now we are processing Encrypted Extensions and
+     * Certificate extensions as part of this one message. Later we need to
+     * split out the Certificate extensions into the Certificate message
+     */
+    if (!tls_collect_extensions(s, &extensions,
+                                EXT_TLS1_3_ENCRYPTED_EXTENSIONS
+                                | EXT_TLS1_3_CERTIFICATE, &rawexts, &al)
+            || !tls_parse_all_extensions(s,
+                                         EXT_TLS1_3_ENCRYPTED_EXTENSIONS
+                                         | EXT_TLS1_3_CERTIFICATE,
+                                         rawexts, &al))
+        goto err;
+
     return MSG_PROCESS_CONTINUE_READING;
 
  err:
diff --git a/ssl/statem/statem_srvr.c b/ssl/statem/statem_srvr.c
index 5aa395f406..d40141d516 100644
--- a/ssl/statem/statem_srvr.c
+++ b/ssl/statem/statem_srvr.c
@@ -1910,15 +1910,10 @@ int tls_construct_server_hello(SSL *s, WPACKET *pkt)
             || !s->method->put_cipher_by_char(s->s3->tmp.new_cipher, pkt, &len)
             || (!SSL_IS_TLS13(s)
                 && !WPACKET_put_bytes_u8(pkt, compm))
-               /*
-                * TODO(TLS1.3): For now we add all 1.2 and 1.3 extensions. Later
-                * we will do this based on the actual protocol
-                */
             || !tls_construct_extensions(s, pkt,
-                                         EXT_TLS1_2_SERVER_HELLO
-                                         | EXT_TLS1_3_SERVER_HELLO
-                                         | EXT_TLS1_3_ENCRYPTED_EXTENSIONS
-                                         | EXT_TLS1_3_CERTIFICATE, &al)) {
+                                         SSL_IS_TLS13(s)
+                                         ? EXT_TLS1_3_SERVER_HELLO
+                                         : EXT_TLS1_2_SERVER_HELLO, &al)) {
         SSLerr(SSL_F_TLS_CONSTRUCT_SERVER_HELLO, ERR_R_INTERNAL_ERROR);
         goto err;
     }
@@ -3495,10 +3490,18 @@ MSG_PROCESS_RETURN tls_process_next_proto(SSL *s, PACKET *pkt)
 
 static int tls_construct_encrypted_extensions(SSL *s, WPACKET *pkt)
 {
-    /* TODO(TLS1.3): Zero length encrypted extensions message for now */
-    if (!WPACKET_put_bytes_u16(pkt, 0)) {
+    int al;
+
+    /*
+     * TODO(TLS1.3): For now we send certificate extensions in with the
+     * encrypted extensions. Later we need to move these to the certificate
+     * message.
+     */
+    if (!tls_construct_extensions(s, pkt, EXT_TLS1_3_ENCRYPTED_EXTENSIONS
+                                          | EXT_TLS1_3_CERTIFICATE, &al)) {
+        ssl3_send_alert(s, SSL3_AL_FATAL, al);
         SSLerr(SSL_F_TLS_CONSTRUCT_ENCRYPTED_EXTENSIONS, ERR_R_INTERNAL_ERROR);
-        ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_INTERNAL_ERROR);
+        ssl3_send_alert(s, SSL3_AL_FATAL, al);
         return 0;
     }