Complete the TLS extension handling rewrite for the server-side.

This removes ssl_parse_clienthello_tlsext() and allows the CBS to be
passed all the way through from ssl3_get_client_hello(). The renegotation
check gets pulled up into ssl3_get_client_hello() which is where other
such checks exist.

The TLS extension parsing now also ensures that we do not get duplicates
of any known extensions (the old pre-rewrite code only did this for some
extensions).

ok inoguchi@

1 files changed, 10 insertions, 9 deletions

diff --git a/src/lib/libssl/ssl_srvr.c b/src/lib/libssl/ssl_srvr.c
index 5d741cdc81..6450623d4a 100644
--- a/src/lib/libssl/ssl_srvr.c
+++ b/src/lib/libssl/ssl_srvr.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_srvr.c,v 1.26 2017/10/12 15:52:50 jsing Exp $ */
+/* $OpenBSD: ssl_srvr.c,v 1.27 2018/01/27 15:30:05 jsing Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -813,7 +813,6 @@ ssl3_get_client_hello(SSL *s)
         int i, j, ok, al, ret = -1, cookie_valid = 0;
         long n;
         unsigned long id;
-        unsigned char *p, *d;
         SSL_CIPHER *c;
         STACK_OF(SSL_CIPHER) *ciphers = NULL;
         unsigned long alg_k;
@@ -843,8 +842,7 @@ ssl3_get_client_hello(SSL *s)
         if (n < 0)
                 goto err;
 
-        d = p = (unsigned char *)s->internal->init_msg;
-        end = d + n;
+        end = (unsigned char *)s->internal->init_msg + n;
 
         CBS_init(&cbs, s->internal->init_msg, n);
 
@@ -1038,14 +1036,17 @@ ssl3_get_client_hello(SSL *s)
                 goto f_err;
         }
 
-        p = (unsigned char *)CBS_data(&cbs);
-
-        /* TLS extensions*/
-        if (!ssl_parse_clienthello_tlsext(s, &p, d, n, &al)) {
-                /* 'al' set by ssl_parse_clienthello_tlsext */
+        if (!tlsext_clienthello_parse(s, &cbs, &al)) {
                 SSLerror(s, SSL_R_PARSE_TLSEXT);
                 goto f_err;
         }
+
+        if (!S3I(s)->renegotiate_seen && s->internal->renegotiate) {
+                al = SSL_AD_HANDSHAKE_FAILURE;
+                SSLerror(s, SSL_R_UNSAFE_LEGACY_RENEGOTIATION_DISABLED);
+                goto f_err;
+        }
+
         if (ssl_check_clienthello_tlsext_early(s) <= 0) {
                 SSLerror(s, SSL_R_CLIENTHELLO_TLSEXT);
                 goto err;