Add server name check when proposeing pre-share key

Signed-off-by: Xiaokang Qian <xiaokang.qian@arm.com>
diff --git a/library/ssl_client.c b/library/ssl_client.c
index 1b59125..bd9edf1 100644
--- a/library/ssl_client.c
+++ b/library/ssl_client.c
@@ -54,6 +54,7 @@
 {
     unsigned char *p = buf;
     size_t hostname_len;
+    size_t cmp_hostname_len;
 
     *olen = 0;
 
@@ -64,8 +65,25 @@
         ( "client hello, adding server name extension: %s",
           ssl->hostname ) );
 
+    ssl->session_negotiate->hostname_mismatch = 0;
     hostname_len = strlen( ssl->hostname );
 
+    cmp_hostname_len = hostname_len < ssl->session_negotiate->hostname_len ?
+                       hostname_len : ssl->session_negotiate->hostname_len;
+
+    if( hostname_len != ssl->session_negotiate->hostname_len ||
+        memcmp( ssl->hostname, ssl->session_negotiate->hostname, cmp_hostname_len ) )
+        ssl->session_negotiate->hostname_mismatch = 1;
+
+    if( ssl->session_negotiate->hostname == NULL )
+    {
+        ssl->session_negotiate->hostname = mbedtls_calloc( 1, hostname_len );
+        if( ssl->session_negotiate->hostname == NULL )
+            return MBEDTLS_ERR_SSL_ALLOC_FAILED;
+        memcpy(ssl->session_negotiate->hostname, ssl->hostname, hostname_len);
+    }
+    ssl->session_negotiate->hostname_len = hostname_len;
+
     MBEDTLS_SSL_CHK_BUF_PTR( p, end, hostname_len + 9 );
 
     /*
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 9741a6e..9238761 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -297,6 +297,18 @@
     }
 #endif /* MBEDTLS_SSL_SESSION_TICKETS && MBEDTLS_SSL_CLI_C */
 
+#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
+    if( src->hostname != NULL )
+    {
+        dst->hostname = mbedtls_calloc( 1, src->hostname_len + 1 );
+        if( dst->hostname == NULL )
+            return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
+
+        memcpy( dst->hostname, src->hostname, src->hostname_len );
+        dst->hostname[src->hostname_len] = '\0';
+    }
+#endif
+
     return( 0 );
 }
 
@@ -1978,6 +1990,11 @@
 #if defined(MBEDTLS_SSL_CLI_C)
     if( session->endpoint == MBEDTLS_SSL_IS_CLIENT )
     {
+#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
+        needed +=  1                        /* hostname_len */
+                 + session->hostname_len;   /* hostname */
+#endif
+
         needed +=   4                       /* ticket_lifetime */
                   + 2;                      /* ticket_len */
 
@@ -2004,6 +2021,19 @@
     memcpy( p, session->resumption_key, session->resumption_key_len );
     p += session->resumption_key_len;
 
+#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) && defined(MBEDTLS_SSL_CLI_C)
+    if( session->endpoint == MBEDTLS_SSL_IS_CLIENT &&
+        session->hostname_len != 0 &&
+        session->hostname != NULL )
+    {
+        /* save host name */
+        p[0] = session->hostname_len;
+        p++;
+        memcpy( p, session->hostname, session->hostname_len );
+        p += session->hostname_len;
+    }
+#endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION && MBEDTLS_SSL_CLI_C */
+
 #if defined(MBEDTLS_HAVE_TIME) && defined(MBEDTLS_SSL_SRV_C)
     if( session->endpoint == MBEDTLS_SSL_IS_SERVER )
     {
@@ -2062,6 +2092,22 @@
     memcpy( session->resumption_key, p, session->resumption_key_len );
     p += session->resumption_key_len;
 
+#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION) && defined(MBEDTLS_SSL_CLI_C)
+    if( session->endpoint == MBEDTLS_SSL_IS_CLIENT )
+    {
+        /* load host name */
+        session->hostname_len = p[0];
+        p += 1;
+        if( end - p < session->hostname_len )
+            return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
+        session->hostname = mbedtls_calloc( 1, session->hostname_len );
+        if( session->hostname == NULL )
+            return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
+        memcpy( session->hostname, p, session->hostname_len );
+        p += session->hostname_len;
+    }
+#endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION && MBEDTLS_SSL_CLI_C */
+
 #if defined(MBEDTLS_HAVE_TIME) && defined(MBEDTLS_SSL_SRV_C)
     if( session->endpoint == MBEDTLS_SSL_IS_SERVER )
     {
@@ -2430,6 +2476,39 @@
 
     return( 0 );
 }
+
+int mbedtls_ssl_reset_hostname( mbedtls_ssl_context *ssl,
+                                const char *hostname,
+                                const char *rec_hostname )
+{
+    /* Initialize to suppress unnecessary compiler warning */
+    size_t rec_hostname_len = 0;
+
+    if( hostname == NULL || rec_hostname == NULL )
+        return( 0 );
+
+    rec_hostname_len = strlen( rec_hostname );
+    if( rec_hostname_len > MBEDTLS_SSL_MAX_HOST_NAME_LEN )
+        return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
+
+    if( rec_hostname_len == strlen( hostname ) &&
+        memcmp( hostname, rec_hostname, rec_hostname_len ) == 0 )
+        return( 0 );
+
+    if( ssl->hostname != NULL )
+    {
+        mbedtls_platform_zeroize( ssl->hostname, strlen( ssl->hostname ) );
+        mbedtls_free( ssl->hostname );
+        ssl->hostname = NULL;
+        ssl->hostname = mbedtls_calloc( 1, rec_hostname_len + 1 );
+        if( ssl->hostname == NULL )
+            return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
+        memcpy( ssl->hostname, rec_hostname, rec_hostname_len );
+        ssl->hostname[rec_hostname_len] = '\0';
+    }
+
+    return( 0 );
+}
 #endif /* MBEDTLS_X509_CRT_PARSE_C */
 
 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
@@ -3679,6 +3758,10 @@
     mbedtls_free( session->ticket );
 #endif
 
+#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
+    mbedtls_free( session->hostname );
+#endif
+
     mbedtls_platform_zeroize( session, sizeof( mbedtls_ssl_session ) );
 }
 
diff --git a/library/ssl_tls13_server.c b/library/ssl_tls13_server.c
index 61a1bad..60b1e05 100644
--- a/library/ssl_tls13_server.c
+++ b/library/ssl_tls13_server.c
@@ -235,6 +235,20 @@
                  (int)age_diff_in_ms ) );
         goto exit;
     }
+#if 0
+#if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
+        if( ssl->session_negotiate->hostname != NULL &&
+            ssl->session_negotiate->hostname_len != 0 &&
+            memcmp( ssl->session_negotiate->hostname,
+            ssl->session->hostname, ssl->session->hostname_len ) != 0 )
+        {
+            MBEDTLS_SSL_DEBUG_MSG(
+            3, ( "Session hostname not matched with stored session ticket" ) );
+            goto exit;
+        }
+
+#endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */
+#endif
 
     ret = 0;