Subject: [PATCH] Revert "Bluetooth: Align minimum encryption key size for LE and BR/EDR connections"

From: Vasily Khoruzhick <[email-masked]>
Date: Tue, 21 May 2019 22:20:02 -0700

This reverts commit d5bb334a8e171b262e48f378bd2096c0ea458265.

This commit breaks some HID devices, see [1] for details

https://bugzilla.kernel.org/show_bug.cgi?id=203643

Signed-off-by: Vasily Khoruzhick <[email-masked]>
Cc: [email-masked]
---
 include/net/bluetooth/hci_core.h | 3 ---
 net/bluetooth/hci_conn.c         | 8 --------
 2 files changed, 11 deletions(-)

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index 05b1b96f4d9e..094e61e07030 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -190,9 +190,6 @@ struct adv_info {
 
 #define HCI_MAX_SHORT_NAME_LENGTH	10
 
-/* Min encryption key size to match with SMP */
-#define HCI_MIN_ENC_KEY_SIZE		7
-
 /* Default LE RPA expiry time, 15 minutes */
 #define HCI_DEFAULT_RPA_TIMEOUT		(15 * 60)
 
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index 3cf0764d5793..bd4978ce8c45 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -1276,14 +1276,6 @@ int hci_conn_check_link_mode(struct hci_conn *conn)
 	    !test_bit(HCI_CONN_ENCRYPT, &conn->flags))
 		return 0;
 
-	/* The minimum encryption key size needs to be enforced by the
-	 * host stack before establishing any L2CAP connections. The
-	 * specification in theory allows a minimum of 1, but to align
-	 * BR/EDR and LE transports, a minimum of 7 is chosen.
-	 */
-	if (conn->enc_key_size < HCI_MIN_ENC_KEY_SIZE)
-		return 0;
-
 	return 1;
 }
 
-- 
2.21.0