ticket_lifetime_hint may exceed 1 week in TLSv1.3

For TLSv1.3, limit ticket lifetime hint to 1 week per RFC8446

Fixes #17948

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Tim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/17952)

(cherry picked from commit 0089cc7f9d42f6e39872161199fb8b6a99da2492)

1 files changed, 15 insertions, 6 deletions

diff --git a/ssl/statem/statem_srvr.c b/ssl/statem/statem_srvr.c
index d701c46b43..79cfd1d835 100644
--- a/ssl/statem/statem_srvr.c
+++ b/ssl/statem/statem_srvr.c
@@ -3820,15 +3820,24 @@ int tls_construct_server_certificate(SSL *s, WPACKET *pkt)
 static int create_ticket_prequel(SSL *s, WPACKET *pkt, uint32_t age_add,
                                  unsigned char *tick_nonce)
 {
+    uint32_t timeout = (uint32_t)s->session->timeout;
+
     /*
-     * Ticket lifetime hint: For TLSv1.2 this is advisory only and we leave this
-     * unspecified for resumed session (for simplicity).
+     * Ticket lifetime hint:
      * In TLSv1.3 we reset the "time" field above, and always specify the
-     * timeout.
+     * timeout, limited to a 1 week period per RFC8446.
+     * For TLSv1.2 this is advisory only and we leave this unspecified for
+     * resumed session (for simplicity).
      */
-    if (!WPACKET_put_bytes_u32(pkt,
-                               (s->hit && !SSL_IS_TLS13(s))
-                               ? 0 : s->session->timeout)) {
+#define ONE_WEEK_SEC (7 * 24 * 60 * 60)
+
+    if (SSL_IS_TLS13(s)) {
+        if (s->session->timeout > ONE_WEEK_SEC)
+            timeout = ONE_WEEK_SEC;
+    } else if (s->hit)
+        timeout = 0;
+
+    if (!WPACKET_put_bytes_u32(pkt, timeout)) {
         SSLfatal(s, SSL_AD_INTERNAL_ERROR, SSL_F_CREATE_TICKET_PREQUEL,
                  ERR_R_INTERNAL_ERROR);
         return 0;