1 files changed, 17 insertions, 0 deletions
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index 1d085eed72d0..e3cd81ce2a7b 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -1163,6 +1163,23 @@ 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;