commit ba5165e09a4f38db594384a446566257cad1fcde
author Ronald Cron <ronald.cron@arm.com> Tue Nov 21 13:53:18 2023 +0100
committer Ronald Cron <ronald.cron@arm.com> Mon Jan 15 08:58:15 2024 +0100
tree 66f50202d79f68fbec81a8b2f09dcea2a2fcba14
parent e34f124ff107783c31c18308af8fd9febc2b74eb

ssl_ticket.c: Fix ticket lifetime enforcement

Take into account that the lifetime of
tickets can be changed through the
mbedtls_ssl_ticket_rotate() API.

Signed-off-by: Ronald Cron <ronald.cron@arm.com>

include/mbedtls/ssl_ticket.h

diff --git a/include/mbedtls/ssl_ticket.h b/include/mbedtls/ssl_ticket.h
index 6d59c12..5842049 100644
--- a/include/mbedtls/ssl_ticket.h
+++ b/include/mbedtls/ssl_ticket.h
@@ -50,6 +50,10 @@
 #if defined(MBEDTLS_HAVE_TIME)
     mbedtls_time_t MBEDTLS_PRIVATE(generation_time); /*!< key generation timestamp (seconds) */
 #endif
+    /*! Lifetime of the key in seconds. This is also the lifetime of the
+     *  tickets created under that key.
+     */
+    uint32_t MBEDTLS_PRIVATE(lifetime);
 #if !defined(MBEDTLS_USE_PSA_CRYPTO)
     mbedtls_cipher_context_t MBEDTLS_PRIVATE(ctx);   /*!< context for auth enc/decryption    */
 #else

library/ssl_ticket.c

diff --git a/library/ssl_ticket.c b/library/ssl_ticket.c
index e47cf42..1ea7a50 100644
--- a/library/ssl_ticket.c
+++ b/library/ssl_ticket.c
@@ -75,6 +75,10 @@
 #if defined(MBEDTLS_HAVE_TIME)
     key->generation_time = mbedtls_time(NULL);
 #endif
+    /* The lifetime of a key is the configured lifetime of the tickets when
+     * the key is created.
+     */
+    key->lifetime = ctx->ticket_lifetime;
 
     if ((ret = ctx->f_rng(ctx->p_rng, key->name, sizeof(key->name))) != 0) {
         return ret;
@@ -116,16 +120,17 @@
 #if !defined(MBEDTLS_HAVE_TIME)
     ((void) ctx);
 #else
-    if (ctx->ticket_lifetime != 0) {
+    mbedtls_ssl_ticket_key * const key = ctx->keys + ctx->active;
+    if (key->lifetime != 0) {
         mbedtls_time_t current_time = mbedtls_time(NULL);
-        mbedtls_time_t key_time = ctx->keys[ctx->active].generation_time;
+        mbedtls_time_t key_time = key->generation_time;
 
 #if defined(MBEDTLS_USE_PSA_CRYPTO)
         psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
 #endif
 
         if (current_time >= key_time &&
-            (uint64_t) (current_time - key_time) < ctx->ticket_lifetime) {
+            (uint64_t) (current_time - key_time) < key->lifetime) {
             return 0;
         }
 
@@ -198,6 +203,8 @@
 #if defined(MBEDTLS_HAVE_TIME)
     key->generation_time = mbedtls_time(NULL);
 #endif
+    key->lifetime = lifetime;
+
     return 0;
 }
 
@@ -331,7 +338,7 @@
 
     key = &ctx->keys[ctx->active];
 
-    *ticket_lifetime = ctx->ticket_lifetime;
+    *ticket_lifetime = key->lifetime;
 
     memcpy(key_name, key->name, TICKET_KEY_NAME_BYTES);
 
@@ -515,7 +522,7 @@
         mbedtls_time_t current_time = mbedtls_time(NULL);
 
         if (current_time < session->start ||
-            (uint32_t) (current_time - session->start) > ctx->ticket_lifetime) {
+            (uint32_t) (current_time - session->start) > key->lifetime) {
             ret = MBEDTLS_ERR_SSL_SESSION_TICKET_EXPIRED;
             goto cleanup;
         }