[PATCH] wifi: brcmfmac: cfg80211: Use WSEC to set SAE password

[Hector Martin]

Using the WSEC command instead of sae_password seems to be the supported
mechanism on newer firmware, and also how the brcmdhd driver does it.

According to user reports [1], the sae_password codepath doesn't actually
work on machines with Cypress chips anyway, so no harm in removing it.

This makes WPA3 work with iwd, or with wpa_supplicant pending a support
patchset [2].

[1] https://rachelbythebay.com/w/2023/11/06/wpa3/
[2] http://lists.infradead.org/pipermail/hostap/2023-July/041653.html

Signed-off-by: Hector Martin <marcan@xxxxxxxxx>
---
 .../broadcom/brcm80211/brcmfmac/cfg80211.c         | 46 +++++++++-------------
 .../broadcom/brcm80211/brcmfmac/fwil_types.h       |  2 +-
 2 files changed, 20 insertions(+), 28 deletions(-)

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
index 2a90bb24ba77..138af70a33b8 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
@@ -1687,52 +1687,44 @@ static u16 brcmf_map_fw_linkdown_reason(const struct brcmf_event_msg *e)
 	return reason;
 }
 
-static int brcmf_set_pmk(struct brcmf_if *ifp, const u8 *pmk_data, u16 pmk_len)
+static int brcmf_set_wsec(struct brcmf_if *ifp, const u8 *key, u16 key_len, u16 flags)
 {
 	struct brcmf_pub *drvr = ifp->drvr;
 	struct brcmf_wsec_pmk_le pmk;
 	int err;
 
+	if (key_len > sizeof(pmk.key)) {
+		bphy_err(drvr, "key must be less than %zu bytes\n",
+			 sizeof(pmk.key));
+		return -EINVAL;
+	}
+
 	memset(&pmk, 0, sizeof(pmk));
 
-	/* pass pmk directly */
-	pmk.key_len = cpu_to_le16(pmk_len);
-	pmk.flags = cpu_to_le16(0);
-	memcpy(pmk.key, pmk_data, pmk_len);
+	/* pass key material directly */
+	pmk.key_len = cpu_to_le16(key_len);
+	pmk.flags = cpu_to_le16(flags);
+	memcpy(pmk.key, key, key_len);
 
-	/* store psk in firmware */
+	/* store key material in firmware */
 	err = brcmf_fil_cmd_data_set(ifp, BRCMF_C_SET_WSEC_PMK,
 				     &pmk, sizeof(pmk));
 	if (err < 0)
 		bphy_err(drvr, "failed to change PSK in firmware (len=%u)\n",
-			 pmk_len);
+			 key_len);
 
 	return err;
 }
 
+static int brcmf_set_pmk(struct brcmf_if *ifp, const u8 *pmk_data, u16 pmk_len)
+{
+	return brcmf_set_wsec(ifp, pmk_data, pmk_len, 0);
+}
+
 static int brcmf_set_sae_password(struct brcmf_if *ifp, const u8 *pwd_data,
 				  u16 pwd_len)
 {
-	struct brcmf_pub *drvr = ifp->drvr;
-	struct brcmf_wsec_sae_pwd_le sae_pwd;
-	int err;
-
-	if (pwd_len > BRCMF_WSEC_MAX_SAE_PASSWORD_LEN) {
-		bphy_err(drvr, "sae_password must be less than %d\n",
-			 BRCMF_WSEC_MAX_SAE_PASSWORD_LEN);
-		return -EINVAL;
-	}
-
-	sae_pwd.key_len = cpu_to_le16(pwd_len);
-	memcpy(sae_pwd.key, pwd_data, pwd_len);
-
-	err = brcmf_fil_iovar_data_set(ifp, "sae_password", &sae_pwd,
-				       sizeof(sae_pwd));
-	if (err < 0)
-		bphy_err(drvr, "failed to set SAE password in firmware (len=%u)\n",
-			 pwd_len);
-
-	return err;
+	return brcmf_set_wsec(ifp, pwd_data, pwd_len, BRCMF_WSEC_PASSPHRASE);
 }
 
 static void brcmf_link_down(struct brcmf_cfg80211_vif *vif, u16 reason,
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwil_types.h b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwil_types.h
index 611d1a6aabb9..b68c46caabe8 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwil_types.h
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fwil_types.h
@@ -584,7 +584,7 @@ struct brcmf_wsec_key_le {
 struct brcmf_wsec_pmk_le {
 	__le16  key_len;
 	__le16  flags;
-	u8 key[2 * BRCMF_WSEC_MAX_PSK_LEN + 1];
+	u8 key[BRCMF_WSEC_MAX_SAE_PASSWORD_LEN];
 };
 
 /**

---
base-commit: ffc253263a1375a65fa6c9f62a893e9767fbebfa
change-id: 20231107-brcmfmac-wpa3-9e5f66e8be34

Best regards,
-- 
Hector Martin <marcan@xxxxxxxxx>