hostapd: SAE/EAP-pwd side-channel attack update

Fixes this security problem:
* SAE/EAP-pwd side-channel attack update
https://w1.fi/security/2019-6/sae-eap-pwd-side-channel-attack-update.txt

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
(cherry picked from commit 7bed9bf10fc8d05df34c7efc66e8b4ade37a1a0c)

1 files changed, 44 insertions, 0 deletions

diff --git a/package/network/services/hostapd/patches/066-0006-dragonfly-Disable-use-of-groups-using-Brainpool-curv.patch b/package/network/services/hostapd/patches/066-0006-dragonfly-Disable-use-of-groups-using-Brainpool-curv.patch
new file mode 100644
index 0000000000..28555bb715
--- /dev/null
+++ b/package/network/services/hostapd/patches/066-0006-dragonfly-Disable-use-of-groups-using-Brainpool-curv.patch
@@ -0,0 +1,44 @@
+From 558518ed63202e5358116ab7e0afd5e85490f2ef Mon Sep 17 00:00:00 2001
+From: Jouni Malinen <j@w1.fi>
+Date: Sat, 27 Jul 2019 23:19:17 +0300
+Subject: [PATCH 6/6] dragonfly: Disable use of groups using Brainpool curves
+
+Disable groups that use Brainpool curves for now since they leak more
+timing information due to the prime not being close to a power of two.
+This removes use of groups 28, 29, and 30 from SAE and EAP-pwd.
+
+Signed-off-by: Jouni Malinen <j@w1.fi>
+(cherry picked from commit 876c5eaa6dae1a87a17603fc489a44c29eedc2e3)
+---
+ src/common/sae.c                | 6 ++++--
+ src/eap_common/eap_pwd_common.c | 3 +--
+ 2 files changed, 5 insertions(+), 4 deletions(-)
+
+--- a/src/common/sae.c
++++ b/src/common/sae.c
+@@ -28,9 +28,11 @@ static int sae_suitable_group(int group)
+ 	 * purposes: FFC groups whose prime is >= 3072 bits and ECC groups
+ 	 * defined over a prime field whose prime is >= 256 bits. Furthermore,
+ 	 * ECC groups defined over a characteristic 2 finite field and ECC
+-	 * groups with a co-factor greater than 1 are not suitable. */
++	 * groups with a co-factor greater than 1 are not suitable. Disable
++	 * groups that use Brainpool curves as well for now since they leak more
++	 * timing information due to the prime not being close to a power of
++	 * two. */
+ 	return group == 19 || group == 20 || group == 21 ||
+-		group == 28 || group == 29 || group == 30 ||
+ 		group == 15 || group == 16 || group == 17 || group == 18;
+ #endif /* CONFIG_TESTING_OPTIONS */
+ }
+--- a/src/eap_common/eap_pwd_common.c
++++ b/src/eap_common/eap_pwd_common.c
+@@ -89,8 +89,7 @@ static int eap_pwd_suitable_group(u16 nu
+ {
+ 	/* Do not allow ECC groups with prime under 256 bits based on guidance
+ 	 * for the similar design in SAE. */
+-	return num == 19 || num == 20 || num == 21 ||
+-		num == 28 || num == 29 || num == 30;
++	return num == 19 || num == 20 || num == 21;
+ }
+ 
+