Hi Marcel,
On Wed, May 20, 2020 at 2:20 PM Luiz Augusto von Dentz
<luiz.dentz@xxxxxxxxx> wrote:
>
> From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
>
> 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>
> ---
> include/net/bluetooth/hci_core.h | 10 ++++++----
> net/bluetooth/hci_conn.c | 17 +++++++++++++++++
> net/bluetooth/hci_event.c | 20 ++++++++------------
> 3 files changed, 31 insertions(+), 16 deletions(-)
>
> diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
> index cdd4f1db8670..c69309ffd40a 100644
> --- a/include/net/bluetooth/hci_core.h
> +++ b/include/net/bluetooth/hci_core.h
> @@ -1402,11 +1402,13 @@ static inline void hci_encrypt_cfm(struct hci_conn *conn, __u8 status)
> else
> encrypt = 0x01;
>
> - if (conn->sec_level == BT_SECURITY_SDP)
> - conn->sec_level = BT_SECURITY_LOW;
> + if (!status) {
> + if (conn->sec_level == BT_SECURITY_SDP)
> + conn->sec_level = BT_SECURITY_LOW;
>
> - if (conn->pending_sec_level > conn->sec_level)
> - conn->sec_level = conn->pending_sec_level;
> + if (conn->pending_sec_level > conn->sec_level)
> + conn->sec_level = conn->pending_sec_level;
> + }
>
> mutex_lock(&hci_cb_list_lock);
> list_for_each_entry(cb, &hci_cb_list, list) {
> diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
> index 307800fd18e6..b99b5c6de55a 100644
> --- a/net/bluetooth/hci_conn.c
> +++ b/net/bluetooth/hci_conn.c
> @@ -1323,6 +1323,23 @@ 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: 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 cfeaee347db3..d6a1e2450696 100644
> --- a/net/bluetooth/hci_event.c
> +++ b/net/bluetooth/hci_event.c
> @@ -3065,27 +3065,23 @@ static void hci_encrypt_change_evt(struct hci_dev *hdev, struct sk_buff *skb)
>
> clear_bit(HCI_CONN_ENCRYPT_PEND, &conn->flags);
>
> + /* Check link security requirements are met */
> + if (!hci_conn_check_link_mode(conn))
> + ev->status = HCI_ERROR_AUTH_FAILURE;
> +
> if (ev->status && conn->state == BT_CONNECTED) {
> if (ev->status == HCI_ERROR_PIN_OR_KEY_MISSING)
> set_bit(HCI_CONN_AUTH_FAILURE, &conn->flags);
>
> + /* Notify upper layers so they can cleanup before
> + * disconnecting.
> + */
> + hci_encrypt_cfm(conn, ev->status);
> hci_disconnect(conn, HCI_ERROR_AUTH_FAILURE);
> hci_conn_drop(conn);
> goto unlock;
> }
>
> - /* In Secure Connections Only mode, do not allow any connections
> - * 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);
> - hci_conn_drop(conn);
> - goto unlock;
> - }
> -
> /* Try reading the encryption key size for encrypted ACL links */
> if (!ev->status && ev->encrypt && conn->type == ACL_LINK) {
> struct hci_cp_read_enc_key_size cp;
> --
> 2.25.3
Looks like we had left this behind.
--
Luiz Augusto von Dentz
