SSL test programs: allow for test hooks init and error reports

Create utility functions to set up test hooks and report errors that
the test hooks might detect. Call them in ssl_client2 and ssl_server2.

Test hooks are potentially enabled by compiling with
MBEDTLS_TEST_HOOKS.

This commit only sets up the functions. It doesn't make them do
anything yet.

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>

programs/ssl/ssl_client2.c

@@ -734,6 +734,8 @@ int main( int argc, char *argv[] )
     mbedtls_memory_buffer_alloc_init( alloc_buf, sizeof(alloc_buf) );
 #endif
 
+    test_hooks_init( );
+
     /*
      * Make sure memory references are valid.
      */
@@ -3036,6 +3038,14 @@ exit:
     mbedtls_free( context_buf );
 #endif
 
+    if( test_hooks_failure_detected( ) )
+    {
+        if( ret == 0 )
+            ret = 1;
+        mbedtls_printf( "Test hooks detected errors.\n" );
+    }
+    test_hooks_free( );
+
 #if defined(MBEDTLS_MEMORY_BUFFER_ALLOC_C)
 #if defined(MBEDTLS_MEMORY_DEBUG)
     mbedtls_memory_buffer_alloc_status();

programs/ssl/ssl_server2.c

@@ -1369,6 +1369,8 @@ int main( int argc, char *argv[] )
 #endif  /* MBEDTLS_MEMORY_DEBUG */
 #endif  /* MBEDTLS_MEMORY_BUFFER_ALLOC_C */
 
+    test_hooks_init( );
+
     /*
      * Make sure memory references are valid in case we exit early.
      */
@@ -3998,6 +4000,14 @@ exit:
     mbedtls_free( context_buf );
 #endif
 
+    if( test_hooks_failure_detected( ) )
+    {
+        if( ret == 0 )
+            ret = 1;
+        mbedtls_printf( "Test hooks detected errors.\n" );
+    }
+    test_hooks_free( );
+
 #if defined(MBEDTLS_MEMORY_BUFFER_ALLOC_C)
 #if defined(MBEDTLS_MEMORY_DEBUG)
     mbedtls_memory_buffer_alloc_status();

programs/ssl/ssl_test_lib.c

@@ -321,4 +321,21 @@ int idle( mbedtls_net_context *fd,
     return( 0 );
 }
 
+#if defined(MBEDTLS_TEST_HOOKS)
+
+void test_hooks_init( void )
+{
+}
+
+int test_hooks_failure_detected( void )
+{
+    return( 0 );
+}
+
+void test_hooks_free( void )
+{
+}
+
+#endif /* MBEDTLS_TEST_HOOKS */
+
 #endif /* !defined(MBEDTLS_SSL_TEST_IMPOSSIBLE) */

programs/ssl/ssl_test_lib.h

@@ -258,5 +258,36 @@ int idle( mbedtls_net_context *fd,
 #endif
           int idle_reason );
 
+#if defined(MBEDTLS_TEST_HOOKS)
+/** Initialize whatever test hooks are enabled by the compile-time
+ * configuration and make sense for the TLS test programs. */
+void test_hooks_init( void );
+
+/** Check if any test hooks detected a problem.
+ *
+ * If a problem was detected, make sure to print an explanation to stderr,
+ * either at the time of detection or during the call to this function.
+ *
+ * \return Nonzero if a problem was detected.
+ *         \c 0 if no problem was detected.
+ */
+int test_hooks_failure_detected( void );
+
+/** Free any resources allocated for the sake of test hooks.
+ *
+ * Call this at the end of the program so that resource leak analyzers
+ * don't complain.
+ */
+void test_hooks_free( void );
+
+#else /* MBEDTLS_TEST_HOOKS */
+
+/* Define macros that do nothing, for convenience. */
+#define test_hooks_init( ) ( (void) 0 )
+#define test_hooks_failure_detected( ) 0
+#define test_hooks_free( ) ( (void) 0 )
+
+#endif /* !MBEDTLS_TEST_HOOKS */
+
 #endif /* MBEDTLS_SSL_TEST_IMPOSSIBLE conditions: else */
 #endif /* MBEDTLS_PROGRAMS_SSL_SSL_TEST_LIB_H */