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 <hlinnaka@iki.fi>
Reported-by: Andres Freund <andres@anarazel.de>
Discussion: https://postgr.es/m/20240617173803.6alnafnxpiqvlh3g@awork3.anarazel.de
Backpatch-through: v12

diff --git a/configure b/configure
index e065cbf64c0e9f1c6436fa1dc26ac514fa9ade02..6ad10dba9ee8de11d6eb62f48a5e884c5d3d85de 100755 (executable)
--- a/configure
+++ b/configure
@@ -13142,12 +13142,13 @@ 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 9eb21e7c9bf4f69c208c70ae400bfe6c627de988..b5a18ab0e7c858f924322acd3e009a219f95de03 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -1323,7 +1323,7 @@ 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 d2064f1473c9629fc822d51c0875357e4fd944bd..70fa303ae5b64756043a9d41e609fd022337e8e6 100644 (file)
--- a/src/backend/libpq/be-secure-openssl.c
+++ b/src/backend/libpq/be-secure-openssl.c
@@ -242,8 +242,20 @@ 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 51fa911fb6aeef7fa7dfe45503c2ad6fe22d29e0..6c1c4916d7f7512572bf7097a344a828288fef78 100644 (file)
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -724,6 +724,9 @@
 /* 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