Bluetooth: Disconnect if E0 is used for Level 4

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@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This commit is contained in:
Luiz Augusto von Dentz 2020-05-20 14:20:14 -07:00 committed by Marcel Holtmann
parent 5cbd3ebde8
commit 8746f135bb
3 changed files with 31 additions and 16 deletions

View File

@ -1481,11 +1481,13 @@ 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) {

View File

@ -1322,6 +1322,23 @@ 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;

View File

@ -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;