Disable all TLS session tickets

OpenSSL supports two types of session tickets for TLSv1.3, stateless
and stateful. The option we've used only turns off stateless tickets
leaving stateful tickets active. Use the new API introduced in 1.1.1
to disable all types of tickets.

Backpatch to all supported versions.

Reviewed-by: Heikki Linnakangas 
Reported-by: Andres Freund 
Discussion: https://postgr.es/m/20240617173803[email protected]
Backpatch-through: v12

diff --git a/configure b/configure
index a13348f3d719e28b0fcd353891ac76e06591423c..1f8d2a2faef970eed89869283ef2718c673e9724 100755 (executable)
--- a/configure
+++ b/configure
@@ -13310,12 +13310,13 @@ fi
 done
 
   # Function introduced in OpenSSL 1.1.1.
-  for ac_func in X509_get_signature_info
+  for ac_func in X509_get_signature_info SSL_CTX_set_num_tickets
 do :
-  ac_fn_c_check_func "$LINENO" "X509_get_signature_info" "ac_cv_func_X509_get_signature_info"
-if test "x$ac_cv_func_X509_get_signature_info" = xyes; then :
+  as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
+ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
+if eval test \"x\$"$as_ac_var"\" = x"yes"; then :
   cat >>confdefs.h <<_ACEOF
-#define HAVE_X509_GET_SIGNATURE_INFO 1
+#define `$as_echo "HAVE_$ac_func" | $as_tr_cpp` 1
 _ACEOF
 
 fi

diff --git a/configure.ac b/configure.ac
index e41a15253ae64e56f8c766ef0228b42862fa7ffd..f98209bddc5e8689f9d7f8a274baab10b3cfb6f2 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -1359,7 +1359,7 @@ if test "$with_ssl" = openssl ; then
   # function was removed.
   AC_CHECK_FUNCS([CRYPTO_lock])
   # Function introduced in OpenSSL 1.1.1.
-  AC_CHECK_FUNCS([X509_get_signature_info])
+  AC_CHECK_FUNCS([X509_get_signature_info SSL_CTX_set_num_tickets])
   AC_DEFINE([USE_OPENSSL], 1, [Define to 1 to build with OpenSSL support. (--with-ssl=openssl)])
 elif test "$with_ssl" != no ; then
   AC_MSG_ERROR([--with-ssl must specify openssl])

diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c
index 4c7e16ca2cac10d96ca642c2d1fe6960b09c486b..ef1b65b443b5e277da3683b97caa0a9303497f64 100644 (file)
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -249,8 +249,20 @@ be_tls_init(bool isServerStart)
        }
    }
 
-   /* disallow SSL session tickets */
+   /*
+    * Disallow SSL session tickets. OpenSSL use both stateful and stateless
+    * tickets for TLSv1.3, and stateless ticket for TLSv1.2. SSL_OP_NO_TICKET
+    * is available since 0.9.8f but only turns off stateless tickets. In
+    * order to turn off stateful tickets we need SSL_CTX_set_num_tickets,
+    * which is available since OpenSSL 1.1.1. LibreSSL 3.5.4 (from OpenBSD
+    * 7.1) introduced this API for compatibility, but doesn't support session
+    * tickets at all so it's a no-op there.
+    */
+#ifdef HAVE_SSL_CTX_SET_NUM_TICKETS
+   SSL_CTX_set_num_tickets(context, 0);
+#else
    SSL_CTX_set_options(context, SSL_OP_NO_TICKET);
+#endif
 
    /* disallow SSL session caching, too */
    SSL_CTX_set_session_cache_mode(context, SSL_SESS_CACHE_OFF);

diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 768e3d719c152a83d8e91f7798d3253f039f77cd..e787d2dec2dc5ad552c086855dbdfd65d41498df 100644 (file)
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -721,6 +721,9 @@
 /* Define to 1 if you have the `X509_get_signature_nid' function. */
 #undef HAVE_X509_GET_SIGNATURE_NID
 
+/* Define to 1 if you have the `SSL_CTX_set_num_tickets' function. */
+#undef HAVE_SSL_CTX_SET_NUM_TICKETS
+
 /* Define to 1 if the assembler supports X86_64's POPCNTQ instruction. */
 #undef HAVE_X86_64_POPCNTQ