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-rw-r--r--crypto/mem_clr.c24
1 files changed, 9 insertions, 15 deletions
diff --git a/crypto/mem_clr.c b/crypto/mem_clr.c
index ab85344eef38..579e9d18251d 100644
--- a/crypto/mem_clr.c
+++ b/crypto/mem_clr.c
@@ -60,22 +60,16 @@
#include <string.h>
#include <openssl/crypto.h>
-unsigned char cleanse_ctr = 0;
+/*
+ * Pointer to memset is volatile so that compiler must de-reference
+ * the pointer and can't assume that it points to any function in
+ * particular (such as memset, which it then might further "optimize")
+ */
+typedef void *(*memset_t)(void *,int,size_t);
+
+static volatile memset_t memset_func = memset;
void OPENSSL_cleanse(void *ptr, size_t len)
{
- unsigned char *p = ptr;
- size_t loop = len, ctr = cleanse_ctr;
-
- if (ptr == NULL)
- return;
-
- while (loop--) {
- *(p++) = (unsigned char)ctr;
- ctr += (17 + ((size_t)p & 0xF));
- }
- p = memchr(ptr, (unsigned char)ctr, len);
- if (p)
- ctr += (63 + (size_t)p);
- cleanse_ctr = (unsigned char)ctr;
+ memset_func(ptr, 0, len);
}