From 9f9b1721e11470e7d01a3673ec902fdf325c8da2 Mon Sep 17 00:00:00 2001
From: Matthias Ringwald <matthias@ringwald.ch>
Date: Wed, 19 Aug 2015 14:43:41 +0200
Subject: [PATCH] sm: manage global signing counter

---
 ble/sm.c | 10 ++++++++++
 ble/sm.h | 13 +++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/ble/sm.c b/ble/sm.c
index b33d1fed3..88f90eaaf 100644
--- a/ble/sm.c
+++ b/ble/sm.c
@@ -137,6 +137,8 @@ static derived_key_generation_t dkg_state;
 // derived from sm_persistent_er
 // ..
 
+static uint32_t     sm_signing_counter = 0;
+
 // random address update
 static random_address_update_t rau_state;
 static bd_addr_t sm_random_address;
@@ -2225,6 +2227,14 @@ void sm_set_ir(sm_key_t ir){
     memcpy(sm_persistent_ir, ir, 16);
 }
 
+void sm_set_signing_counter(uint32_t signing_counter){
+    sm_signing_counter = signing_counter;
+}
+
+uint32_t sm_signing_counter_next(void){
+    return sm_signing_counter++;
+}
+
 // Testing support only
 void sm_test_set_irk(sm_key_t irk){
     memcpy(sm_persistent_irk, irk, 16);
diff --git a/ble/sm.h b/ble/sm.h
index 41c973a56..80b8ca0da 100644
--- a/ble/sm.h
+++ b/ble/sm.h
@@ -147,6 +147,14 @@ void sm_set_er(sm_key_t er);
  */
 void sm_set_ir(sm_key_t ir);
 
+/**
+ * @brief Set signning counnter used with Connection Signature Resolving Key (CSRK)
+ * @note Needs to be stored in persistent memory as a signed writes are invalid if a higher counter was 
+ *       recevied before
+ * @param signing counter
+ */
+void sm_set_signing_counter(uint32_t signing_counter);
+
 /**
  *
  * @brief Registers OOB Data Callback. The callback should set the oob_data and return 1 if OOB data is availble
@@ -263,6 +271,11 @@ void sm_authorization_grant(uint8_t addr_type, bd_addr_t address);
 int  sm_cmac_ready(void);
 void sm_cmac_start(sm_key_t k, uint16_t message_len, uint8_t * message, uint32_t sign_counter, void (*done_handler)(uint8_t hash[8]));
 
+/**
+ * @brief Get global signing counter and increment it
+ */
+uint32_t sm_signing_counter_next(void);
+
 /*
  * @brief Match address against bonded devices
  * @return 0 if successfully added to lookup queue