netdev - [RFC net-next 01/14] wireguard: netlink: use WG_KEY

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250904220255.1006675-1-ast@fiberby.net>
Date: Thu,  4 Sep 2025 22:02:35 +0000
From: Asbjørn Sloth Tønnesen <ast@...erby.net>
To: "Jason A. Donenfeld" <Jason@...c4.com>,
	"David S. Miller" <davem@...emloft.net>,
	Eric Dumazet <edumazet@...gle.com>,
	Jakub Kicinski <kuba@...nel.org>,
	Paolo Abeni <pabeni@...hat.com>
Cc: Asbjørn Sloth Tønnesen <ast@...erby.net>,
	Donald Hunter <donald.hunter@...il.com>,
	Simon Horman <horms@...nel.org>,
	Jacob Keller <jacob.e.keller@...el.com>,
	Andrew Lunn <andrew+netdev@...n.ch>,
	wireguard@...ts.zx2c4.com,
	netdev@...r.kernel.org,
	linux-kernel@...r.kernel.org
Subject: [RFC net-next 01/14] wireguard: netlink: use WG_KEY_LEN in policies

When converting the netlink policies to YNL, then the constants
used in the policy has to be visible to user-space.

As NOISE_*_KEY_LEN isn't visible for userspace, then change to
use WG_KEY_LEN, as is also documented in the UAPI header:

$ grep WG_KEY_LEN include/uapi/linux/wireguard.h
 *    WGDEVICE_A_PRIVATE_KEY: NLA_EXACT_LEN, len WG_KEY_LEN
 *    WGDEVICE_A_PUBLIC_KEY: NLA_EXACT_LEN, len WG_KEY_LEN
 *            WGPEER_A_PUBLIC_KEY: NLA_EXACT_LEN, len WG_KEY_LEN
 *            WGPEER_A_PRESHARED_KEY: NLA_EXACT_LEN, len WG_KEY_LEN
 [...]

Add a couple of BUILD_BUG_ON() to ensure that they stay in sync.

No behavioural changes intended.

Signed-off-by: Asbjørn Sloth Tønnesen <ast@...erby.net>
---
 drivers/net/wireguard/netlink.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireguard/netlink.c b/drivers/net/wireguard/netlink.c
index 67f962eb8b46..086edd4bb33b 100644
--- a/drivers/net/wireguard/netlink.c
+++ b/drivers/net/wireguard/netlink.c
@@ -22,8 +22,8 @@ static struct genl_family genl_family;
 static const struct nla_policy device_policy[WGDEVICE_A_MAX + 1] = {
 	[WGDEVICE_A_IFINDEX]		= { .type = NLA_U32 },
 	[WGDEVICE_A_IFNAME]		= { .type = NLA_NUL_STRING, .len = IFNAMSIZ - 1 },
-	[WGDEVICE_A_PRIVATE_KEY]	= NLA_POLICY_EXACT_LEN(NOISE_PUBLIC_KEY_LEN),
-	[WGDEVICE_A_PUBLIC_KEY]		= NLA_POLICY_EXACT_LEN(NOISE_PUBLIC_KEY_LEN),
+	[WGDEVICE_A_PRIVATE_KEY]	= NLA_POLICY_EXACT_LEN(WG_KEY_LEN),
+	[WGDEVICE_A_PUBLIC_KEY]		= NLA_POLICY_EXACT_LEN(WG_KEY_LEN),
 	[WGDEVICE_A_FLAGS]		= NLA_POLICY_MASK(NLA_U32, __WGDEVICE_F_ALL),
 	[WGDEVICE_A_LISTEN_PORT]	= { .type = NLA_U16 },
 	[WGDEVICE_A_FWMARK]		= { .type = NLA_U32 },
@@ -31,8 +31,8 @@ static const struct nla_policy device_policy[WGDEVICE_A_MAX + 1] = {
 };
 
 static const struct nla_policy peer_policy[WGPEER_A_MAX + 1] = {
-	[WGPEER_A_PUBLIC_KEY]				= NLA_POLICY_EXACT_LEN(NOISE_PUBLIC_KEY_LEN),
-	[WGPEER_A_PRESHARED_KEY]			= NLA_POLICY_EXACT_LEN(NOISE_SYMMETRIC_KEY_LEN),
+	[WGPEER_A_PUBLIC_KEY]				= NLA_POLICY_EXACT_LEN(WG_KEY_LEN),
+	[WGPEER_A_PRESHARED_KEY]			= NLA_POLICY_EXACT_LEN(WG_KEY_LEN),
 	[WGPEER_A_FLAGS]				= NLA_POLICY_MASK(NLA_U32, __WGPEER_F_ALL),
 	[WGPEER_A_ENDPOINT]				= NLA_POLICY_MIN_LEN(sizeof(struct sockaddr)),
 	[WGPEER_A_PERSISTENT_KEEPALIVE_INTERVAL]	= { .type = NLA_U16 },
@@ -642,6 +642,9 @@ static struct genl_family genl_family __ro_after_init = {
 
 int __init wg_genetlink_init(void)
 {
+	BUILD_BUG_ON(WG_KEY_LEN != NOISE_PUBLIC_KEY_LEN);
+	BUILD_BUG_ON(WG_KEY_LEN != NOISE_SYMMETRIC_KEY_LEN);
+
 	return genl_register_family(&genl_family);
 }
 
-- 
2.51.0