commit 346177255931fb1e3514e124a1f598715a5fe92d
author Paul Bakker <p.j.bakker@polarssl.org> Fri Jun 13 17:20:13 2014 +0200
committer Paul Bakker <p.j.bakker@polarssl.org> Sat Jun 14 16:46:03 2014 +0200
tree da658994944be861b8b2a1001c9b759976276891
parent bbcb1ce7030575d708700ca205800e847d846402

Introduce polarssl_zeroize() instead of memset() for zeroization

library/memory_buffer_alloc.c

diff --git a/library/memory_buffer_alloc.c b/library/memory_buffer_alloc.c
index 7dfeda9..81862fc 100644
--- a/library/memory_buffer_alloc.c
+++ b/library/memory_buffer_alloc.c
@@ -52,6 +52,11 @@
 #define polarssl_fprintf fprintf
 #endif
 
+/* Implementation that should never be optimized out by the compiler */
+static void polarssl_zeroize( void *v, size_t n ) {
+    volatile unsigned char *p = v; while( n-- ) *p++ = 0;
+}
+
 #define MAGIC1       0xFF00AA55
 #define MAGIC2       0xEE119966
 #define MAX_BT 20
@@ -578,7 +583,7 @@
 #if defined(POLARSSL_THREADING_C)
     polarssl_mutex_free( &heap.mutex );
 #endif
-    memset( &heap, 0, sizeof(buffer_alloc_ctx) );
+    polarssl_zeroize( &heap, sizeof(buffer_alloc_ctx) );
 }
 
 #endif /* POLARSSL_MEMORY_BUFFER_ALLOC_C */