systemd/SOURCES/1009-resolved-reduce-the-maximum-nsec3-iterations-to-100.patch

35 lines
1.4 KiB
Diff

From 92124e84be68005be92cce046c7c679b98199d66 Mon Sep 17 00:00:00 2001
From: Jacek Migacz <jmigacz@redhat.com>
Date: Mon, 26 Feb 2024 13:56:36 +0100
Subject: [PATCH] resolved: reduce the maximum nsec3 iterations to 100
According to RFC9267, the 2500 value is not helpful, and in fact it can
be harmful to permit a large number of iterations. Combined with limits
on the number of signature validations, I expect this will mitigate the
impact of maliciously crafted domains designed to cause excessive
cryptographic work.
(cherry picked from commit eba291124bc11f03732d1fc468db3bfac069f9cb)
Related: RHEL-26644
---
src/resolve/resolved-dns-dnssec.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/src/resolve/resolved-dns-dnssec.c b/src/resolve/resolved-dns-dnssec.c
index 5dbfbc94c7..5a0540568c 100644
--- a/src/resolve/resolved-dns-dnssec.c
+++ b/src/resolve/resolved-dns-dnssec.c
@@ -22,8 +22,9 @@
/* Permit a maximum clock skew of 1h 10min. This should be enough to deal with DST confusion */
#define SKEW_MAX (1*USEC_PER_HOUR + 10*USEC_PER_MINUTE)
-/* Maximum number of NSEC3 iterations we'll do. RFC5155 says 2500 shall be the maximum useful value */
-#define NSEC3_ITERATIONS_MAX 2500
+/* Maximum number of NSEC3 iterations we'll do. RFC5155 says 2500 shall be the maximum useful value, but
+ * RFC9276 § 3.2 says that we should reduce the acceptable iteration count */
+#define NSEC3_ITERATIONS_MAX 100
/*
* The DNSSEC Chain of trust: