Bluetooth: Add support for handling signature resolving keys

The connection signature resolving key (CSRK) is used for attribute
protocol signed write procedures. This change generates a new local
key during pairing and requests the peer key as well.

Newly generated key and received key will be provided to userspace
using the New Signature Resolving Key management event.

The Master CSRK can be used for verification of remote signed write
PDUs and the Slave CSRK can be used for sending signed write PDUs
to the remote device.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

2 files changed, 20 insertions, 0 deletions

diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
index dbb788e4f265..e869884fbfa9 100644
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -91,6 +91,13 @@ struct bt_uuid {
         u8 svc_hint;
 };
 
+struct smp_csrk {
+        bdaddr_t bdaddr;
+        u8 bdaddr_type;
+        u8 master;
+        u8 val[16];
+};
+
 struct smp_ltk {
         struct list_head list;
         bdaddr_t bdaddr;
@@ -1265,6 +1272,7 @@ int mgmt_device_blocked(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 type);
 int mgmt_device_unblocked(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 type);
 void mgmt_new_ltk(struct hci_dev *hdev, struct smp_ltk *key);
 void mgmt_new_irk(struct hci_dev *hdev, struct smp_irk *irk);
+void mgmt_new_csrk(struct hci_dev *hdev, struct smp_csrk *csrk);
 void mgmt_reenable_advertising(struct hci_dev *hdev);
 void mgmt_smp_complete(struct hci_conn *conn, bool complete);
 
diff --git a/include/net/bluetooth/mgmt.h b/include/net/bluetooth/mgmt.h
index 0326648fd799..d4b571c2f9fd 100644
--- a/include/net/bluetooth/mgmt.h
+++ b/include/net/bluetooth/mgmt.h
@@ -551,3 +551,15 @@ struct mgmt_ev_new_irk {
         bdaddr_t rpa;
         struct mgmt_irk_info irk;
 } __packed;
+
+struct mgmt_csrk_info {
+        struct mgmt_addr_info addr;
+        __u8 master;
+        __u8 val[16];
+} __packed;
+
+#define MGMT_EV_NEW_CSRK                0x0019
+struct mgmt_ev_new_csrk {
+        __u8 store_hint;
+        struct mgmt_csrk_info key;
+} __packed;