The patch was authored by Marcus Meissner <meissner@suse.com> on 2015-07-13
to address weak DH size vulnerability.

--- openldap-2.4.26.orig/libraries/libldap/tls_o.c
+++ openldap-2.4.26/libraries/libldap/tls_o.c
@@ -1190,7 +1190,6 @@ jT6sx7RUr0CNTxzLI7muV2/a4tGmj0PSdXQdsZ7t
 -----END DH PARAMETERS-----\n";
 
 static const struct dhinfo tlso_dhpem[] = {
-	{ 512, tlso_dhpem512, sizeof(tlso_dhpem512) },
	{ 1024, tlso_dhpem1024, sizeof(tlso_dhpem1024) },
	{ 2048, tlso_dhpem2048, sizeof(tlso_dhpem2048) },
	{ 4096, tlso_dhpem4096, sizeof(tlso_dhpem4096) },
@@ -1205,6 +1204,9 @@ tlso_tmp_dh_cb( SSL *ssl, int is_export,
	DH *dh = NULL;
	int i;
 
+	/* for Logjam, rev up the minimum DH group size to 1024 bit */
+	if (key_length < 1024) key_length = 1024;
+
	/* Do we have params of this length already? */
	LDAP_MUTEX_LOCK( &tlso_dh_mutex );
	for ( p = tlso_dhparams; p; p=p->next ) {