commit 842be1680097c23429c3c307b782c79fa18aa654
author Jarno Lamsa <jarno.lamsa@arm.com> Mon Jun 10 15:05:33 2019 +0300
committer Jarno Lamsa <jarno.lamsa@arm.com> Mon Jun 10 15:05:33 2019 +0300
tree 563b79d7d8a2d6f56553b2b5efdc0a6e07ac88c9
parent d9382f85e7b8f5d518a4ad713045f2891b705280

Check for the enforcing and fail handshake if the peer doesn't support

library/ssl_cli.c

diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index be80de7..64870b1 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -2090,6 +2090,21 @@
     }
 #endif /* MBEDTLS_SSL_RENEGOTIATION */
 
+    /*
+     * Check if extended master secret is being enforced
+     */
+#if defined(MBEDTLS_SSL_EXTENDED_MASTER_SECRET)
+    if( ssl->conf->extended_ms == MBEDTLS_SSL_EXTENDED_MS_ENABLED &&
+        ssl->conf->enforce_extended_master_secret ==
+        MBEDTLS_SSL_EXTENDED_MS_ENFORCE_ENABLED &&
+        ssl->handshake->extended_ms == MBEDTLS_SSL_EXTENDED_MS_DISABLED)
+    {
+        MBEDTLS_SSL_DEBUG_MSG( 1, ( "Peer not offering extended master "
+                                    "secret, while it is enforced") );
+        handshake_failure = 1;
+    }
+#endif /* MBEDTLS_SSL_EXTENDED_MASTER_SECRET */
+
     if( handshake_failure == 1 )
     {
         mbedtls_ssl_send_alert_message( ssl, MBEDTLS_SSL_ALERT_LEVEL_FATAL,