Commit 5bbdc26c authored by Andy Polyakov's avatar Andy Polyakov
Browse files

crypto/mem_clr.c: switch to OPENSSL_cleanse implementation from master. 



It's probably worth reminding that this is a fall-back implementation
for platforms that don't have assembly OPENSSL_cleanse.

Reviewed-by: default avatarRich Salz <rsalz@openssl.org>
parent 4f0b6e67

crypto/mem_clr.c

+9 −15
Original line number Diff line number Diff line
@@ -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);

}