Feature/mbedtls (#84)

* try to import mbedtls and build it

* add stubs socket class

* some boilterplate, read and write function implemented

* more boilterplate / current error in handshake because no CA cert is setup

* add something so skip ca verification, can ws curl https://google.com !

* cleanup / close implemented

* tweak CMakefiles

* typo in include

* update readme

* disable unittests

third_party/mbedtls/tests/suites/test_suite_timing.function

@@ -0,0 +1,74 @@
+/* BEGIN_HEADER */
+
+/* This test module exercises the timing module. Since, depending on the
+ * underlying operating system, the timing routines are not always reliable,
+ * this suite only performs very basic sanity checks of the timing API.
+ */
+
+#include <limits.h>
+
+#include "mbedtls/timing.h"
+
+/* END_HEADER */
+
+/* BEGIN_DEPENDENCIES
+ * depends_on:MBEDTLS_TIMING_C
+ * END_DEPENDENCIES
+ */
+
+/* BEGIN_CASE */
+void timing_hardclock( )
+{
+    (void) mbedtls_timing_hardclock();
+    /* This goto is added to avoid warnings from the generated code. */
+    goto exit;
+}
+/* END_CASE */
+
+/* BEGIN_CASE */
+void timing_get_timer( )
+{
+    struct mbedtls_timing_hr_time time;
+    (void) mbedtls_timing_get_timer( &time, 1 );
+    (void) mbedtls_timing_get_timer( &time, 0 );
+    /* This goto is added to avoid warnings from the generated code. */
+    goto exit;
+}
+/* END_CASE */
+
+/* BEGIN_CASE */
+void timing_set_alarm( int seconds )
+{
+    if( seconds == 0 )
+    {
+        mbedtls_set_alarm( seconds );
+        TEST_ASSERT( mbedtls_timing_alarmed == 1 );
+    }
+    else
+    {
+        mbedtls_set_alarm( seconds );
+        TEST_ASSERT( mbedtls_timing_alarmed == 0 ||
+                     mbedtls_timing_alarmed == 1 );
+    }
+}
+/* END_CASE */
+
+/* BEGIN_CASE */
+void timing_delay( int fin_ms )
+{
+    mbedtls_timing_delay_context ctx;
+    int result;
+    if( fin_ms == 0 )
+    {
+        mbedtls_timing_set_delay( &ctx, 0, 0 );
+        result = mbedtls_timing_get_delay( &ctx );
+        TEST_ASSERT( result == -1 );
+    }
+    else
+    {
+        mbedtls_timing_set_delay( &ctx, fin_ms / 2, fin_ms );
+        result = mbedtls_timing_get_delay( &ctx );
+        TEST_ASSERT( result >= 0 && result <= 2 );
+    }
+}
+/* END_CASE */