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

[Neal Gompa <neal@gompa.dev>]

On Tue, Nov 7, 2023 at 1:06 AM Hector Martin <marcan@marcan.st> wrote:
>
> 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@marcan.st>
> ---
>  .../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@marcan.st>
>
>

Looks good to me.

Reviewed-by: Neal Gompa <neal@gompa.dev>



--
真実はいつも一つ！/ Always, there's only one truth!