From: William Lallemand <wlallemand@haproxy.com>
Date: Fri, 14 Aug 2026 09:07:12 +0000 (+0000)
Subject: MINOR: ssl-gencert: enforce a stronger seed for the LRU cache key
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=21ba33f12d936764f868b6561f7d5e677b241139;p=thirdparty%2Fhaproxy.git

MINOR: ssl-gencert: enforce a stronger seed for the LRU cache key

The generated-certificate LRU cache key is seeded with the process
start time (time(NULL)).

This is not considered a bug per se: 'generate-certificates' is
generally deployed in MITM/interception contexts where the operator
already controls both ends of the connection. Still, relying on the
process start time for this seed is fragile, so switch to
ha_random64(), which is seeded at boot from /dev/urandom and
OpenSSL's RAND_bytes().
---

diff --git a/src/ssl_gencert.c b/src/ssl_gencert.c
index f57c655ff..b608f552c 100644
--- a/src/ssl_gencert.c
+++ b/src/ssl_gencert.c
@@ -15,6 +15,7 @@
 #include <haproxy/quic_ssl.h>
 #include <haproxy/ssl_ckch.h>
 #include <haproxy/ssl_sock.h>
+#include <haproxy/tools.h>
 #include <haproxy/xxhash.h>
 
 #if (defined SSL_CTRL_SET_TLSEXT_HOSTNAME && !defined SSL_NO_GENERATE_CERTIFICATES)
@@ -440,7 +441,8 @@ ssl_sock_gencert_load_ca(struct bind_conf *bind_conf)
 	if (global_ssl.ctx_cache) {
 		ssl_ctx_lru_tree = lru64_new(global_ssl.ctx_cache);
 	}
-	ssl_ctx_lru_seed = (uint64_t)time(NULL);
+	/* unpredictable seed, must not be guessable from the outside */
+	ssl_ctx_lru_seed = ha_random64();
 	ssl_ctx_serial   = now_ms;
 #endif