Hi Luiz,
> E0 is not allowed with Level 4:
>
> BLUETOOTH CORE SPECIFICATION Version 5.2 | Vol 3, Part C page 1319:
>
> '128-bit equivalent strength for link and encryption keys
> required using FIPS approved algorithms (E0 not allowed,
> SAFER+ not allowed, and P-192 not allowed; encryption key
> not shortened'
>
> SC enabled:
>
>> HCI Event: Read Remote Extended Features (0x23) plen 13
> Status: Success (0x00)
> Handle: 256
> Page: 1/2
> Features: 0x0b 0x00 0x00 0x00 0x00 0x00 0x00 0x00
> Secure Simple Pairing (Host Support)
> LE Supported (Host)
> Secure Connections (Host Support)
>> HCI Event: Encryption Change (0x08) plen 4
> Status: Success (0x00)
> Handle: 256
> Encryption: Enabled with AES-CCM (0x02)
>
> SC disabled:
>
>> HCI Event: Read Remote Extended Features (0x23) plen 13
> Status: Success (0x00)
> Handle: 256
> Page: 1/2
> Features: 0x03 0x00 0x00 0x00 0x00 0x00 0x00 0x00
> Secure Simple Pairing (Host Support)
> LE Supported (Host)
>> HCI Event: Encryption Change (0x08) plen 4
> Status: Success (0x00)
> Handle: 256
> Encryption: Enabled with E0 (0x01)
> [May 8 20:23] Bluetooth: hci0: Invalid security: expect AES but E0 was used
> < HCI Command: Disconnect (0x01|0x0006) plen 3
> Handle: 256
> Reason: Authentication Failure (0x05)
>
> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
> ---
> net/bluetooth/hci_conn.c | 17 +++++++++++++++++
> net/bluetooth/hci_event.c | 6 ++----
> 2 files changed, 19 insertions(+), 4 deletions(-)
>
> diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
> index 07c34c55fc50..0c1cae83c8dc 100644
> --- a/net/bluetooth/hci_conn.c
> +++ b/net/bluetooth/hci_conn.c
> @@ -1325,6 +1325,23 @@ int hci_conn_check_link_mode(struct hci_conn *conn)
> return 0;
> }
>
> + /* AES encryption is required for Level 4:
> + *
> + * BLUETOOTH CORE SPECIFICATION Version 5.2 | Vol 3, Part C
> + * page 1319:
> + *
> + * 128-bit equivalent strength for link and encryption keys
> + * required using FIPS approved algorithms (E0 not allowed,
> + * SAFER+ not allowed, and P-192 not allowed; encryption key
> + * not shortened)
> + */
> + if (conn->sec_level == BT_SECURITY_FIPS &&
> + !test_bit(HCI_CONN_AES_CCM, &conn->flags)) {
> + bt_dev_err(conn->hdev, "Invalid security: expect AES but E0 "
> + "was used");
make this bt_dev_warn since it is something that can happen. We fail appropriately now. Also try to fit the error in a single line. “Invalid security: Missing AES-CCM usage”.
> + return 0;
> + }
> +
> if (hci_conn_ssp_enabled(conn) &&
> !test_bit(HCI_CONN_ENCRYPT, &conn->flags))
> return 0;
> diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
> index 006c24e04b44..dc1cc3c4348c 100644
> --- a/net/bluetooth/hci_event.c
> +++ b/net/bluetooth/hci_event.c
> @@ -3078,10 +3078,8 @@ static void hci_encrypt_change_evt(struct hci_dev *hdev, struct sk_buff *skb)
> * that are not encrypted with AES-CCM using a P-256 authenticated
> * combination key.
> */
> - if (hci_dev_test_flag(hdev, HCI_SC_ONLY) &&
> - (!test_bit(HCI_CONN_AES_CCM, &conn->flags) ||
> - conn->key_type != HCI_LK_AUTH_COMBINATION_P256)) {
> - hci_connect_cfm(conn, HCI_ERROR_AUTH_FAILURE);
> + if (!hci_conn_check_link_mode(conn)) {
> + hci_disconnect(conn, HCI_ERROR_AUTH_FAILURE);
Why is this a disconnect now? If this is better, then this needs to be explained above, but I have the feeling we really want to respond to the connect request in a clean fashion.
> hci_conn_drop(conn);
> goto unlock;
Regards
Marcel
