BLE Nordic: Initialize and teardown tls platform context

Author: pan-

features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NRF52/source/nRF5xCrypto.cpp

@@ -47,6 +47,7 @@ namespace vendor {
 namespace nordic {
 
 CryptoToolbox::CryptoToolbox() : _initialized(false) {
+    mbedtls_platform_setup(&_platform_context);
     mbedtls_entropy_init(&_entropy_context);
     mbedtls_ecp_group_init(&_group);
     int err = mbedtls_ecp_group_load(
@@ -59,6 +60,7 @@ CryptoToolbox::CryptoToolbox() : _initialized(false) {
 CryptoToolbox::~CryptoToolbox() {
     mbedtls_ecp_group_free(&_group);
     mbedtls_entropy_free(&_entropy_context);
+    mbedtls_platform_teardown(&_platform_context);
 }
 
 bool CryptoToolbox::generate_keys(

features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NRF52/source/nRF5xCrypto.h

@@ -132,6 +132,7 @@ class CryptoToolbox : mbed::NonCopyable<CryptoToolbox> {
     void swap_endian(uint8_t* buf, size_t len);
 
     bool _initialized;
+    mbedtls_platform_context _platform_context;
     mbedtls_entropy_context _entropy_context;
     mbedtls_ecp_group _group;
 };